On the "A&P Help..." thread you will see my study tips which basically outlined how I studied. I hope that helps!

I was nearly done with my first semester of Chemistry and A&P I when I took it, but that helped a lot. Mainly, I got the study guide (I used the old study guide that you can only get used on Amazon.com now), studied the vocabulary and dumb stuff like Roman Numerals. I used the study guide to clue me in to which areas of bio and chem I needed to focus on. (I didn't have to take the A&P portion of the HESI). Anything I didn't understand or needed a quick review of, I went to sparknotes.com. Sparknotes.com has really great, concise explanations of many things (like DNA replication). Look in their AP test prep areas; I found those sections the best. Good luck!