As John says please don't feel stupid, maybe feel a little angry that the Government and our governing bodies allow it to happen freely.
Take your time in deciding whether or not the installer and the system are going to work for you, never be pushed into a sale by any installer. The decision time is the longest part of the whole process, the installation is relatively quick in comparison so make sure you have a complete understanding of:
How the FIT works?
How does PV work?
How can PV improve our lives?
How do you install my system, I want to see installation procedures from start to finish.
The technology used and why? There are more products available now that can improve system performance and you should have an understanding of how they work so that you can make an informed decision as to which ones to go for.
There is also a great deal of information on these forums so have a read through, this will help you through the process.
Take care and happy hunting for Solar.