I'm using lippencott for Biochem right now. I think its an easier read than many textbooks. Also at the end of each chapter they have concept maps that i think are really helpful to put everything together
in my opinion... no way should you use lippincott for boards studying. it's a good study aid for you biochem class in med school, but boards does not emphasize biochem at all (5% of questions tops) and you should spend a max of 2 days reviewing the major pathways and biochemical problems that cause disease.
i spent about one day going thru kaplan's board review section for biochem and read usmle first aid biochem section 3 times to prepare. it's just that lippincott's is an order of magnitude too detailed. you should know pathways like the urea cycle/purine catabalism/tca cycle/one-carbon metabolism and the major metabolic diseases, but not a whole lot else.
re: general studies for usmle step 1 i used qbank, first aid, and the kaplan review books with quite a bit of success (260+). other people used brs review books and various other boards review materials... but usually not subject text books for review.