For a GR intro, I really liked Foster and Nightingale's "A Short Course in General Relativity" because it progresses very naturally like this:
1. Curvilinear coordinate systems in flat space (e.g. polar or spherical)
2. Curvilinear coordinate systems for a curved surface in flat space (e.g. a spherical surface)
3. Specialize to remaining in that curved surface, and now you have a curved 2d space. Suddenly we are in GR land.
If you already know what the Jacobian is and how to transform between (x,y) and (r,theta) in flat 2d, then you can quickly get up to speed. If not, he introduces these things, and you'll just have to move a little more slowly.