Help on birthday portraits/shots

[dbose]

Hi all - I have been concentrating on landscape photography and realized I need to get better at portraits as well (given I have a family with kids and I need to stay married )

Actually my son's 5th birthday is coming up next week. It'll be at a restaurant in the evening with low light conditions - orange walls and white ceilings. I shoot with D90 and have a SB600 speed light. I am trying to get as many tips and techniques to get it right (composition, filters if any, settings etc.). He'll be wearing white shirt, a blue vest and trousers with about 120 guests.

I'll be bouncing the flash off a neutral surface, iTTL meter and shoot. However, I am a bit confused with the metering - I generally use spot metering. With metering do I meter the shot from the skin colors or clothes? Also how would spot metering (or center weighted) work if I have to work with relatively faster shutter speed in manual mode? Say if at F5.6 the meter reads a shutter speed of 1/10 th of a second it would be too slow and I'd have to move to a faster speed and rely on ttl flash. So how would metering work?

I would really appreciate some assistance pelase...

[tanz]

Sorry I can't help you at all as I am new to photography but I really wanted to wish you good luck - a 5 year olds b'day party with 120 guests, that's gotta be hard work, and hopefully a lot of fun