To add to Ben's post, I'm finding it useful to go through Bhikkhu Bodhi's manual in parallel with Nina van Gorkom's Abhidhamma in Daily Life (ADL), which you can download here: http://www.zolag.co.uk/
This is my second time through these books and they are finally starting to make some sense. They provide a useful contrast. The Material the Bhikkhu Bodhi has assembled is very thorough, with many tables of cittas and cetasikas, whereas Nina is much more conversational. Nina has other downloadable books which might also be useful to read in this parallel manner, particularly the one on Cetasikas.