Kayak guide here...
Blisters form because of friction, as many know. What most don't realize is that it matters little if your hands are wet or dry. Because you are gripping the paddle tightly, your hands will rub against the paddle plastic.
Depending on how you are holding it, you want to minimize the "sliding", try to keep your hands on the same place on the kayak paddle - don't move them up and down the paddle shaft as some do. I usually open/close (flex) my "highest" hand when I am paddling (i.e. my lower hand is down by the water, pulling me forward, and the other hand is higher up the paddle, keep it in line). The biggest place for a blister is the inside edge of your thumb, between your thumb and first finger, so move your thumb around as you paddle to different positions; your thumb doesn't always have to wrap around the paddle.
I still developed small callouses, but little by way of blisters. Never used gloves personally - I would only recommend them for part-time paddlers (3-5 times/year - any more than that, start working on callouses, it is worth it for longer paddles) as it really reduces friction and makes beginners more comfortable. You may want gloves if you're doing much whitewater/rougher water (rapids, lots of rocks) since you may be trying to push off rocks/trees, etc., but the focus should always be on your paddle and using it properly).
For reference, REI.com stocks a few pairs (link).