Amateur prepares to shoot a sweet 16

A co-worker saw my photos of my baby and asked me to shoot her daughter's sweet 16. I am an amateur looking for some advice. I have started to read advice for people like me who are asked to shoot weddings and thought I might get some more specific advice here.

First, this is a simple favor. I am not replacing a pro, and so I do not feel compelled to do a truly professional job, but I would like to do my best. My equipment and experience is obviously limited. I am open to low-budget purchases, e.g. I will need a decent tripod and a flash. I may like to add a lens or two, but this can get pricey.

My equipment will be my newer micro 4/3 and older canon dslr.

1. Panasonic GF1
20mm 1.7
Rokkor MD 50mm 1.8
Rokkor MC 135mm 2.8

2. Canon 300D
kit 28-55mm
Sigma 70-300 f3.5-5.6
Canon 50mm f/1.8

Specifically:
I could use general advice
I could use flash / diffuser advise.
I could use tripod advise.
I could use links to good reading online.

Maybe I will use the SLR with a longer lens (although the 70-300 is slow) for candids. Perhaps the GF1 with Rokkor 50mm for posed shots.

Budget is low, maybe $100 or less for tripod; about the same for flash equipment; can spend a bit more on lenses if I need too.

neil