You already got a ton of great info and I just wanted to add some testing tips:
You want to use "THIN" lancets. "Thin" is thicker than "Ultra Thin" or "Micro Thin". Once your cats ears "learn to bleed", you can use the 30 gauge lancets.
As you poke, the body will start to grow more capillaries into the area to "heal the wound", so even if you don't necessarily get a good blood sample, in the long run it'll get easier and easier.
It can be really helpful to establish a routine with testing. Pick one spot that you want your "testing spot" to be (I like the kitchen counter because it's got good light and it's at a good height....it also already blocked 2 escape routes due to the wall and the backsplash) It can be anywhere though...a rug on the floor, a table, a particular spot on the couch...wherever is good for you. After Minnie got used to testing, the spot didn’t matter anymore. I could literally test her anywhere she happened to be and she was fine with it.
Take him there as many times a day as you can and just give his ears a quick rub and then he gets a yummy (low carb) treat. Most cats aren't objecting so much with the poking..it's the fooling with their ears they don't like, but once they're desensitized to it and learn to associate a certain place with the treats, they usually start to come when they're called! Or even when they hear us opening the test kit!
You also have to remember...you're not poking him to hurt him...you're testing him to keep him safe and understand what's going on inside his body. There's just nothing better than truly understanding what's going on inside your kitty's body and with this disease, the more knowledge you have, the more power you have against it. The edges of the ears have very few pain receptors, so it really doesn't hurt them. Also, if you're nervous and tense, it's going to make your kitty nervous and tense too. As silly as it might seem, try singing! It forces you to use a different part of your brain!
It's also important to make sure his ear is warm. A small sock filled with a little rice and microwaved or a small pill bottle filled with warm water (check temp against your wrist like you would a baby bottle) works well
For new kitties, using a heavier gauge lancet is also really helpful. A 25-28 gauge lancet pokes a bigger "hole" than a 31-33 gauge lancet does, so look for "Alternate Site testing" lancets that are usually a lower number
Finding the right "treat" will be a great help too! Freeze dried chicken, bonito flakes, little pieces of baked chicken...whatever low carb treat you can find that he really enjoys will help him to associate the testing with the treat!
There are more testing tips here:
http://www.felinediabetes.com/FDMB/threads/hometesting-links-and-tips.287/