Since Open Translation is an emergent field, examples of best practice community management are rare. However it is possible to learn a lot from the history of community development especially as it has emerged in the free software and free content sectors (there is much research available on these topics at the Open Source MIT Research Community - http://opensource.mit.edu/online_papers.php)
One of the keys to success lies in developing an understanding of why people would like to contribute to your project and methods to grow their involvement, and keep them satisfied and involved. In some cases these approaches might be very simple - for example, you may simply have the funds available to pay people so some or all of the contributors will be motivated through remuneration. However it is often the case that online communities consist entirely of volunteers or they simultaneously consist of full time staff, part time staff, and volunteers. For this type of community a different approach is required.
Volunteers can join a project for a variety of reasons - they might think your cause is a good one and want to help, they might love the topic, they could enjoy interaction with other community members, they might wish to become better at translation, they might be looking to do something with their skills during boring office hours. Each of these factors may come in to play and have different weighting according to the individual. Hence, it is difficult to come up with general rules about how to attract and maintain volunteers. However experience in free software development has shown that there are some things that you can do that might help (Karl Fogel has an excellent chapter about this topic in his book 'Producing Open Source' : http://producingoss.com/en/managing-volunteers.html).
Many projects actually appoint a community manager. Actually, most volunteer communities have someone acting in this role even if they do not realise it. At the beginning of a project this role is probably fulfilled by the person or persons that founded the project but as a project gets larger new people may need to be found to manage the larger capacity of work being done by the organisation and so new community managers may emerge from the volunteer base of they may need
to be appointed.
It might take a long time until you get your first voluntary contribution; when it comes in, it is exciting and could well be a day you remember for a long time! After that point the process of building a community can be slow. To draw people in you need to have an inspiring story and ways to get the message out. However, once people know about who you are and what you do, only a small percentage will offer to volunteer. When they do you should be ready with a clear entry path for them so they can get involved quickly and feel productive. You can then draw them in bit by bit and grow their role over time. When they become proficient then experienced volunteers can help mentor other new comers.
You should also think of every user of your service as being a potential volunteer. There are many tricks to this. For example, if someone finds a spelling mistake on your website you might write back with a humorous message saying "congratulations, you found our hidden spelling mistake - we have found this is a proven method for identifying good proof readers - would you like to help?" Personable and humourous messages like this can be very effective in getting people interested in being involved.
In addition to communicating what the organisation does, a community manager may need to do a lot of communicating with the volunteers themselves. This might take place through email, blogs, chat applications etc. It could even involve old technologies like the telephone or a room with table and chairs.
With all communication, whether in real space or done via technology, remember that most volunteers don't have to do anything. They are present because of their own good will, and there are likely other things they could do if they weren't helping you achieve the goals of your organisation. Hence it is always good to keep this in mind and make the process of being involved a positive and engaging social experience that they will want to continue to engage in. This social experience might simply be a rewarding one-to-one communication with you about specific tasks to be done, or it could consist of more fun and frivolous chatter. Whichever the case, it is up to the community manager to work out which method works best for whom.
Over time, capacity may become an issue for the community manager. When a community grows beyond a certain point it is sometimes very difficult to stay current with all correspondence with all volunteers. In this situation it is good to draw upon the others in your core group to assist. If these core group members are also volunteers they may welcome the trust you put in them to help fulfil this role.
In communications with volunteers it is also always a good idea to provide encouraging and positive comments and to illustrate a clear understanding of the work the volunteer has been doing for your organisation. This is particularly true if the community manager is also the founder, or an esteemed member of the community, since many volunteers are sensitive to the opinions of people in this kind of position.
It is also a good idea to congratulate and praise specific volunteers for their work in public and private channels.
It is sometimes also necessary to manage disruptive people. This should be done, where possible, on a one-to-one basis with direct and clear feedback or directives. Occasionally it might be necessary to communicate issues through community communication channels but you should be very careful doing this. Generally speaking, only light matters of protocol violation should be politely pointed out through normal channels. Truly sensitive communications should be personal wherever possible. If you feel you are about to send a turgid communication through a community email list, for example, it is often better to step back a little, give yourself time to cool down and then re-evaluate your approach.
Occasionally you may make a mistake and blame someone for something that was not their fault. In this case an apology is always necessary, especially if the original communication was open to the scrutiny of others.
It is often said that you cannot pay volunteers for fear of demotivating them. This may seem unintuitive - why would anyone mind being paid? However in economic theory there is a phenomenon called 'crowding out' - it refers to exactly this kind of issue. One study in particular looked at a school where parents organised a volunteer schedule for picking up children after school. Parents would share the task of picking the children up after school and delivering them to their respective homes. In this case study the school thought this a very good idea and decided to pay parents to continue to do this. What they found was that parents, who were originally motivated by the idea they were doing something for the good of the community, now felt obliged to do the job and became resentful and less inclined to participate. This is known as the Crowding Out phenomenon and it is thought to also apply to online volunteer communities.
However it is also unclear how this factor is effected by other factors. For example, establishing a cultural norm early where it is ok to be occasionally paid might in turn counter the Crowding Out effect.
The point here really boils down to two simple truths. The first is that issues surrounding payment need to be thought through and it might not always be that 'norms' like 'being paid is good' have the expected results. Secondly, if you are a community manager in the field of Open Translation then you will need to form your own theories and try them out.
Most volunteers wish to know that the work they do actually has an effect. For this reason it is always a good idea to communicate loudly what your organisation does and how the work of the volunteers positively effects these outcomes.