A few responses.
– The speed of gravity is the speed of light, though that is not quite as firm as some of the other results in modern physics. It seems that they have stopped arguing over it.
– I can’t recommend a good book on SR, just because I don’t have any handy. You can go over the to Bad Astronomy / Universe Today forum and ask there, I’m sure someone will have several.
– If you want a good introduction to Relativity and much of physics go watch “The Mechanical Universe” It was a set of videos done at Cal Tech in the 80’s and goes over most or all of what would be in freshman physics. You can find them over at Google Video.