Why not just solve the centers intuitively? That's what i did. I started cubing about 2 months ago and learned the beginners method for the 3x3x3. Once i had the 3x3x3 down, i bought myself a 2x2x2, 4x4x4, and 5x5x5, which i solved intuitively. Solving the 5x5x5 centers are very simple in my opinion.