You should do a search through this section and the book review section, because this has come up several times before.
I suggest Schutz, A First Course in General Relativity, because he does a good job on special relativity and introduces all the necessary math.
Comments on some other books:
Rindler, Relativity: Special, General, and Cosmological. Very thorough on SR, and lots of insight on everything, but might frustrate the mathematically inclined reader.
Ohanian & Ruffini, Graviation and Spacetime. Very physical book, but not quite enough on SR for a beginner.
Carroll, Spacetime and Geometry. Great book, very modern, practical, and reads very well, but pretty much assumes mastery of SR.
Misner, Thorne & Wheeler, Gravitation. Too fat and eccentric for a first book. But many libraries have it, and it's fun to explore.
Wald, General Relativity. Too sophisticated and advanced for an introduction.