The SignRequest API-documentation is available online and contains many examples and the most important client libraries. We constantly update the API documentation based on the feedback we receive from our users. All with the intent to make it as easy as possible to integrate.
SignRequest developers can offer support (online meetings, email, Skype etc) for your API questions and help guide the implementation process. We however do not do the actual integration for you. In our experience the majority of the work is often actually on the side of the customer application. Therefore, we believe it's best that the team of developers that work on your application is also the team that does the implementation of SignRequest.