If you look, my solid color ones are fastened with Velcro, and the multi-colored one has snaps. Again, it's all in preference. Velcro does wear out, which is something to consider. Another vocabulary lesson: gussets are the extra piece of elastic lined fabric that is sewn in around the part that goes around the thigh. See the picture below:Gussets help with holding in the moisture. I don't suggest covers that don't have gussets.
Dealing with the Dirty Diapers
There's two options: a wet pail, and a dry pail. I use a wet pail. I have a 5 gallon bucket that I put Oxi-Clean and water in, and throw the dirty diapers and covers in there to soak until I'm ready to wash them. I highly recommend a wet pail if you'll be washing with a front-loader like I do. Also, please keep the wet pail somewhere out of a children's reach. Think: drowning hazard. A dry pail is done by using a wet bag (fabric bag lined in PUL) or an actual covered bin. A bit of tea tree oil in the pail keeps the smells inside.
How to wash them just depends on who you talk to. I suggest you really research yourself on what type of detergent to use. However, every CD mom will tell you a few of the same things on what to do: 1. Do NOT use a detergent with fragrance and stuff, because it contains soap. I don't know why that's bad, but I know it is. I think it messes with the absorbency of the diapers. 2. Do NOT use fabric softener...also messes with absorbency. 3. Do NOT dry your covers in the dryer - always line dry them. The heat will, over time, ruin the PUL layer and they wont be waterproof anymore. 4. If you have Velcro covers, make sure the Velcro is fastened so you don't make a diaper chain in your washer. I had to learn this the hard way, and also messed with the gussets on one of my covers and had to throw it away. It was a sad day.
There is much controversy on whether or not there are any regular store-bought detergents that are ok for CD's. But, there are lots of CD-specific detergents, so when in doubt, those are always a safe choice since they're designed for CD's.
For info on washing CD's in a front loader, check out my separate post on that subject.
Other CD things to consider that I don't think I'm knowledgeable enough to give my opinion on: *cloth wipes *disposable liners *fitted diapers *diaper services (Doesn't save you much money-if any-but is still good for the environment compared to disposables.)