What exactly is your math background? "A bit of math" is quite vague. General relativity, in order to understand it in all its mathematical beauty, requires differential geometry (the geometry of curved spaces). But if you just want to get a taste of what General Relativity is like, you can also learn about it phenomenologically from a math-light perspective, or you can look at it from a historical perspective as well.
If your background is strong, you can't really go wrong with Misner, Thorne and Wheeler's Gravitation. It is massive, and quite complete (at least as far as its age will allow), but is basically good for a graduate physics level course in general relativity (it does, however, develop special relativity in its opening chapters). This would NOT be my first recommendation for the subject, but more as a reference for when you get more acquainted with GR.
Bernrd Schutz's A First Course in General Relativity is perhaps a better introductory text, but it still assumes a physics and math background. It's probably at the level of a senior undergraduate or beginning graduate course. If Schutz is not clicking with you, you might try Hartle's Gravity, an Introduction to Einstein's General Relativity.
It's hard for me to recommend a more "easy" book than those though, since I learned GR formally by taking graduate courses in it. The only other book that I might recommend is Lillian R Lieber's The Einstein Theory of Relativity. It's quite a unique book, and an easy read. The math is understandable from a high school math background, and she really does develop tensor calculus! The problem with this book though, is it is quite outdated, and looks at general relativity from a much older mathematical perspective (more tensor calculus than differential geometry). As a first book, though, it might not be bad.