Reeldancer, typically one semester of a college class is considered one year of a high school class. However, opinions will differ among homeschoolers. You can do what works best for your homeschool.
Vivian, you called your transcript "unofficial." Be creative. Title the transcript "Official Homeschool Transcript." If they want it sealed, send it sealed with your signature across the back. If they want it in an official envelope, type OFFICIAL HOMESCHOOL TRANSCRIPT in the return address. You want to read the college's language and translate it to your situation. I highly recommend Lee Binz's "Setting the Records Straight" book to anyone who is looking for homeschool transcript advice. (Or just google and check out her blog.)