My husband is a Type 1 diabetic, so I understand where you're coming from!
We use the USDA nutrient database for carbs on on ingredients. And, it's free! You can use it online or you can download to your PC (but not if you're running Vista!) or PDA to make it more convenient. The link is:Nutrient Data Products and Services
As far as any other hints, one thing you'll really want to have around is a kitchen scale. We always one out on the counter so that we can quickly weigh things (in grams) and estimate the carbs by an estiimate of how much starch is in each thing. For example, I made goetta today and that can be one of those thing that's hard to figure, especially since a lot of the oatmeal in it usually sticks to the pan. So, for something like that, I weigh the amount I cook and then asssume that 25% of that weight is carbs. Breads and cookies and such at higher in carbs - maybe 50% to 75%. When we're adding honey or sugar to tea or coffee, we just put the cup on the scale and weigh how much we put in and, for things like sugar and honey, we assume that the whole weight is carbs.
It's also helpful to use recipes that give measurements in weight to help you get an idea of the % of carbs in the finished product.
I hope this helps! If you have any other questions, let me know.