Washing is both the simplest and hardest part of cloth diapering. When it works, it works. When it doesn't, it drives you crazy.
Do's and Don'ts:
DO start out simple. If what you are doing doesn't work, THEN start experimenting to fix problems. If you have problems, go to the DS forums and post, there are other mams that have fixed the same issues and they can speak to how they did it. Or email me, I'll help if I can.
DON'T use fabric softener. Or anything else that can cause "repelling", or affect the absorbency of the diaper.
DO start with a cold rinse. For breastfed baby poo, this rinse gets the runny poo off the dipes. For babies on formula or solids, you will want to dunk-and-swish, or use a diaper sprayer, before storing in the wet bag. This rinse will get the majority of the "stuff" off the diapers, so the hot water won't set stains. Detergent in this step is optional - I usually put just a little Tide in, or now that we use Thirsties, this is where I use the pre-wash.
DO wash your diapers on hot. Hot water kills germs. Just do it. Use less than the normal amount of detergent - halfway to the first line for Tide powder or liquid, or the recommended amount of Thirsties Super Wash.
DO end with an extra rinse. This will get all the suds out. You don't need 2 or 3 or 4, that becomes overkill. If you need more than one additional rinse, you're using too much detergent.
DO check the rinse water to look for suds. Especially when you are working out exactly how much detergent to use, check to see what the results are. If you still have suds in your last rinse, use less detergent.
DON'T use bleach. Again too harse for baby's skin - and the fabric. Bleach can not only discolor your beautiful diapers, but can break down the fabric. Bleach is very bad for PUL. Oxyclean? Here's my take - NO. A cloth diaper seller has written a booklet that says Oxyclean is great and to use it once a month. I did, and my baby got a rash. A rash that it took multiple washes in a natural detergent to get rid of. Unless you really need it, stay away. If you do use it, make sure you get it all out of your diapers. This may take several washes.
DON'T use Dawn in every wash. I read online that a mama tried this, and it really helped with her stinkies. I tried it and gave my baby a rash. Washing with a squirt of Dawn - or even better, boiling in Dawn - is great for stripping and getting off the errant diaper cream that the babysitter got everywhere. For every wash it's too harsh on your baby's skin.
DO hang your diapers outside to dry every once in a while in the sun. The UV rays in sunlight will kill microorganisms, and so this sometimes helps with the stinkies. Sunlight also bleaches stains out of dipes naturally, so if you have a stain that bothers you, lay the dipe in the sun for several hours.
But, DON'T worry if you dry your diapers in the dryer all the time, it won't hurt them.
(Don't let your infant help you with the folding!)
When I started doing diaper laundry, I used Tide powder. I washed her clothes in Dreft, and her diapers in Tide. She developed a rash that looked like a contact dermatitis. It was all over her chest and back, but not her diaper area. Her doctor asked what detergent we used, and we decided that she was probably sensitive to the fragrance in Dreft. Since she didn't have the rash in her diaper area, he suggested I just wash everything in Tide. Tide for diapers worked for us for a very long time, until I also started using Dawn and Oxyclean, and my Wee One got a rash from an antibiotic. All that happened at the same time, so I can't pinpoint an exact cause. All I know is that it sucked. Around that time, I won the Thirsties cloth diaper washes in a giveaway. The diapers accidentally got washed several times, and on the next wearing ... NO RASH.
Added: As always, I wrote this post from my perspective as a single mama. I should add another DO for mamas with parenting partners or other folks living with them. DO either (a) make sure your partner is well versed in diaper laundry, or (b) agree with them that you will be in charge of the diaper laundry. I have read many stories online of an errant hubby ruining a diaper by thinking he is "helping". When I was staying with my parents, my dad "helped" by putting the diapers in the dryer - only they had just been through a rinse, and not a wash, so they got a little stained. One idea I had was to put a dry-erase board near the washer, so you can write what "step" the diapers are on. That way another person helping with the laundry will know they need another rinse before drying, or that they haven't even been washed yet, etc. If you are sharing diaper responsibilities, this might be an idea. I just opted to tell my dad he didn't have to "help" with the laundry anymore!