Thank you for asking the question about detergents...
I don't know what your majority of fluff is...Softbums or others, so that will probably make a difference in my answer.
For Softbums, like you can read in the post below, I use Purex free and clear and I use no softners (beware of detergents that have softeners...like Dreft) because they inhibit absorption. I use Purex because that is what Sarah recommended to me, and it works great. I think that as long as your baby doesn't have a reaction to something, that you can use that. Purex is only soap, nothing else, which is in theory, less likely to cause a reaction with your baby...but all babies are different. You just want the best next to baby's skin. Watch for rashes, they can occur at anytime, an allergy can develop at anytime.
I have heard of babies reacting to All Free and Clear, my lil guy didn't, that is what we use for his cloths, and i have used it on his diapers by accident, and it works fine. I also found Oxyclean free and clear, and use that once in a while, but I never notice anything "cleaner" than it was before. I've been using my softbums since Mason was a month old (now 6.5 months) and only have 1-2 inserts that are stained...and that is because daycare was rinsing them and then they'd sit wet...
If you are using white prefolds, I would say bleach away, and then rinse to get the bleach out of the diapers, but as you know...bleach is for cottons...don't bleach anything other than cottons. (this is what my mom did when I was a baby, I was in bleached prefolds)
I'd also say, if I could, don't use regular detergents like Tide or Era...or anything of the like...way to harsh of soaps for bub's skin. Remember, your baby's poops aren't hard to remove, they will come right out...they aren't a grass stain or a grease stain...it's a baby poop... :)
I think the biggest thing to remember whatever you use will be next to your little guy/gal's butt all day, you want it to be as sensitive as possible. Even if your lo doesn't have a reaction, sitting in soap all day isn't going to be the best for their skin.
If you're following Softbums' directions, wash once in cold on large then once in hot, and using only 1/4 of the detergent that is recommended by the manufacturer, you will be removing a majority of the soap, but not all...you can never remove everything.
Look into all natural soaps, like "Charlies Soap" and "Allens Naturally Laundry Soap"
I am not endorsing this site nor approving everything they say but just googling keywords "Cloth diaper detergent" I found this website: http://www.pinstripesandpolkadots.com/detergentchoices.htm
Notice everything they recommend is free and clear/delicate, etc.
Remember you will end up with stains...it is a fact of life and cloth diapering...the best way to remove stains is by line drying diapers in the sun.
Bottom line: Use what works best for you, start out with something and change if you like something different. Purex Free and Clear works best for me, it is cheap, and I have no reason to look to try something different. Wash once and rinse once (wash w/o detergent...read my posts below if you haven't yet) That is my recommendation.