Hi!
I cut my teeth on a c15 - similar bike, just a little older than a starfire. I think you've picked a good bike to start with. they're easy to work on and a good introduction into the joys of british biking. If you're going to build one, i would strongly recommend the Rupert Ratio Unit Single Manual. It will tell you everything you need to know about the mechanics of these bikes.
Let me know if you have any questions.
Nigel.