This section does not need to be very long, since most people will be well-served by one of the leading manuals. They are all used widely.
VSL Associates offers free downloads of its manuals for Field Officers and Village Agents, and in two versions: normal, and Sharia-compliant. Many are available in the languages that you probably want them in. They are all free downloads from http://www.vsla.net. Registration is required, but it's quick and easy.
Sometimes people assume that Hugh Allen, who wrote all of these manuals, is always right. Hugh would be the first to deny this. When you use his manuals, a safe course is to follow them to the letter, but if you have a good reason to make changes, go ahead.
Also, note that these are primarily procedures manuals, not training manuals. Hugh says this himself: "We have deliberately avoided suggesting a step-by-step training system, since implementing organisations may have their own pedagogical approach." So - it's up to you to figure out how to get people to learn this stuff, and how to test them so that you feel confident turning them loose, once you have trained them.
Many agencies have taken the VSL Associates manual and tweaked it to their own needs. We won't mention most of them here, but there is one that you should know about: Food for the Hungry has produced an excellent manual that includes the procedures of the VSL Associates manuals, but enriched with new and sometimes unexpected materials from other sources. And, it is a complete training manual, with exercises and stories. If you are thinking of training people in the VSL approach, you should definitely take a look at their manual. Please read and respect the limitations on the manual's use on page iii.
Now, something different: CRS has developed a remarkable set of tools: the Savings and Internal Lending Communities Field agent guide, and the Private Service Provider Implementation Manual. The first is about forming and training savings groups, and the second is about putting in place networked trainers (called Private Service Providers, or PSPs) who will continue old groups and form new groups post-project. These are super manuals, reflecting great care and thought, and when the recommended procedures are followed, they deliver, guiding agents to form strong groups, and to continue after the project.
However, another caveat: I have visited old networks of PSPs, and didn't like what I saw. You may wonder, what happens when the PSPs have trained nearly everyone in their region? What happens then? I have seen three ways that PSP networks have dealt with the crisis of the diminishing market: wither they slowly run out of people to train, and the PSPs gradually drift away; or, they pressure existing groups into accepting on-going weekly training, even for four and five years; or, they come up with some scheme to create a financial institution, through which they can aggregate and manage the members' money - this never ends well. I know the smart people at CRS are thinking about how to design for a soft landing better. I recommend the CRS approach, but keep thinking about the exit strategy and what happens next. And then what? And after that?
And here is something even more different: the Saving For Change manuals. These lead to the creation of memory-based, paperless groups. These groups are not flexible enough for some people, who would be better served by groups with paper or digital records. They are, however, just right for many millions of people, mostly women, whose needs are small, who live in remote areas, and whose educational levels are low. The manuals are full of training activities and learning objectives - they make the job of training trainers relatively easy. You can find all of these manuals on the SEEP site.
Finally, one of the Saving for Change partners, Freedom from Hunger, has developed some short video animations that take trainers all the way through the process of forming groups. These are very useful, but unfortunately not yet in the public domain. You can see a sample here, and if you think you might want to use the set, then just contact Freedom from Hunger (try firstname.lastname@example.org).