Lady Belle's advice is spot on. There is a lot of misinformation about GI out there, with people thinking a shred of carrot will cause a blood sugar spike. It is important to keep GL (glycimic load) in mind and books like new glucose revolution explain this, and might be a good read later on. It can be complicated though, and I think the tables in Atkins for life provide an excelent simplification.

And remember that some tables will vary, within reason, becuase they draw on different primary studies. Individual blood sugar responses vary by person - so use GI/GL/Atkins tables as a guide, but remember to always trust your hunger-o-meter and cravings-o-meter.