First, wait and see if your big sib has any books to give you or to lend you.
Second, there's a used book sale that's nice to pick up some books.
1st semester:
You will NEED Netter. I'd recommend your own copy of that so you can mark it up.
Do NOT buy the embryology book. Biochem is survivable without a text, but there are some board review books with questions. The course has changed a fair bit since I was in it, when they made us take a cumulative final dag'nabbit. You youngins have it easy!
The anatomy text isn't 100% necessary, I bought it and read it occasionally.
I didn't become a voracious textbook reader until second semester, and my grades probably reflected that.
At the book sale, try to get BRS phys, Guyton, and Wheater's.