I'd recommend Language of the Dragon, by Gregory Chiang. It might be a little too easy for you if you've already done Mencius before, but I think it's a good starting book for explaining structure and meaning of words. I also used A First Course in Literary Chinese, by Harold Shadick (but it was too old-school for my tastes) and Literary Chinese Reading Selections, compiled by TLI (all in Chinese, no explanation of structure, just modern Chinese definitions of the more difficult vocabulary).