I love your little Fisher. I would love to have one about that size. It will serve you well as long as your are working with small stock. You'll need something bigger as you progress, of course.
I used BBQ briquettes the first few times with my forge (mine was made from car wheel instead of a brake drum). It worked OK as long as I was using VERY small stock. Down here you can buy real hardwood charcoal at Lowes, Wal-mart, and even some grocery stores...I assume you also can where you are? You will be MUCH happier using REAL charcoal instead of the briquettes. If you can't find hardwood charcoal or coal, a lot of folks burn corn. I haven't tried it myself but I understand that it works great!
You're off to a good start...keep it up!