If it's anything important or even if you're not sure, I'd recommend shooting in the largest resolution/fine mode. Delete what you don't want but you'll have a higher quality original to work with.

The difference between fine and normal is in the amount of compression that's applied. When the camera creates a jpeg, it throws away a lot of redundant information. The more even-toned the shot is, the more redundant data there is. IOW, shoot a whole frame of an open blue sky or a polar bear in a snow storm and you'll get a small file (comparatively) but shoot something very detailed with a lot of colors and the file size will be bigger. When you reduce quality to normal, you're lowering the threshold of what's kept versus thrown out. This might lead to problems down the road if you want to make a high-quality print. So - if I had to pick I'd go for the smaller file size and fine mode; but would still recommend what I said above. Memory cards are cheap!