Yo! Like the above people have said, you are in for a whole lot of fun.
I knew almost nothing my entire rookie year. The summer afterward, I read
Kickin' Bot by Grant Imahara. It's a book on the basics of building combat robots. No, FRC is not combat robotics. However, there is a lot of overlap in their construction and basic systems. A lot of stuff I had seen throughout the year started to make a whole lot of sense. I thought the book covered the basics of building a robot very,
very well. It goes through a ton of basic things, from skid-steer drive to roller chain and sprockets to speed controllers to shop tools to motors to ... You get the picture.
I would
highly recommend this book to anyone starting FRC. It doesn't go into much advanced stuff, but, like I said, I thought it covered the basics of building a robot very,
very well. If you can possibly get your hands on a copy of it, I think it'd definitely be worth it.
Have fun!