You will probably not be surprised to hear, that we are pretty minimalist when it comes to cloth diapering accessories. In addition to our diapers, covers, and wipes, we have only a few other helpers.
The first and most important are wet bags and a pail liner. I have a cute wet bag and travel wipes case to match the diaper bag, but it is good to have a back up wet bag too, in case you bring one home with dirty diapers in it, and need to go out again before you can wash it.
My wet bag is from American Country Designs on Etsy, but I like the ones I make better because the front zip is easier to use, and mine are attached inside so the pul doesn't turn inside out in the wash and have to be re stuffed. My wet bags are $14 for all PUL, or $20 with an outer layer of designer cotton print at tentrevival.etsy.com. You can get a 10% discount by using coupon code BLOGREADER.
For a diaper pail we use a small trash can with a Bummis Large Tote as a liner. It used to have a lid to contain the smell, which I'm sure is still around somewhere, but now it lives in the laundry room behind closed doors, so it wasn't used as much and is currently in hiding. I think I paid $16 for mine, but they are $18 now at Cottonbabies.com, which always has free shipping. We love this pail liner because it is really thick and sturdy, it fits our little pail perfectly, it is the least expensive we've found, and it has a drawstring for traveling.
We don't have a diaper sprayer, but I really want one for getting stickier messes off without having to dunk and swish. Who wants to touch that? Yuck. You can get the bumgenius on for $45 at Cottonbabies, it is the mostly popular. The fuzzibunz one is usually $34-$38 on Amazon. Or you can make your own, like in this tutorial for a lot less.
As far as detergent is concerned, there are about a hundred different types, and you can sample them all, or you can trust me when I say that Allen's Naturally Biodegradable is wonderful. The $52/gallon price tag might scare you off, but it uses only 1/4 oz per diaper load, and 1 oz or so per regular load (we use less), so it lasts 6 months or more. The gallon comes with a pump which makes it so easy to use, and I really trust with it that there is nothing left on our clothes after the wash. Use coupon code GOODWASH at Cottonbabies for free detergent shipping. This save a lot since a gallon is so heavy
I want to say here as well that while most cloth diapering websites will tell you you can't use store bought detergent on cloth diapers (anything with softeners, brighteners, or enzymes) We did so for six months or more before ever having any residue problems, and this could have been just because we were using really thick prefolds that needed extra rinsing.
Many websites have various "stripping" instructions for removing stinky residues from your diapers, but I have recently heard that you can use ammonia neutralizer made for fish tanks. It is a very harmless chemical (gentle enough for goldfish to live in) and gets to the source of what is making your diapers smell funny when wet.
Basically every once in a while you may need to run your diapers through a few extra rinses in case there is any build up. Anything "free and clear" will probably not be terrible for your diapers. Even regular powdered tide has quite a large following on Diaperswappers.com.