Hi M.,
First of all - cheers and hugs to you for being a stay at home mom!! Best job in the world and most important! I too am a SAHM though I was a professional (instructional designer and trainer) before I became PG...never went back and have never regretted it. I wanted to encourage you because I know there can be a lot of different pressures that try to push a woman toward going back to the work world, including sometimes financial, but this time when your kids are little goes by SO FAST, and your being there makes all the difference. It has for my daughter and in fact our whole family. SAHMs rock!! God will provide - He gave you your kids and He's cheering you on! :)
As far as the stains - you have my empathy, I hate laundry stains! Ugh! I noticed OxyClean mentioned, which is a good one for soaking out stains. Here are some things that work for me (haven't seen a couple of them mentioned yet):
Soilove is a great stain remover and is unbelievably cheap too. In the East Bay you can find it at Safeway in the laundry section in a green plastic bottle. It's literally less than $2.00 for a good sized bottle. You can squirt it on, or as I like to do for convenience, put it in a clean spray bottle so you can spray it on. It takes out almost everything I have ever tried it on.
For blood and grease, the only thing even better than Soilove is a little set of stain removers by Carbona called Stain Devils (yeah, an unfortunate name!). Here is a link to see them:
http://www.carbona.com/index.asp?PageAction=VIEWCATS&...
In the East Bay they are available at Joann Fabrics, and may be in other fabric stores, I haven't looked. They used to be at Target or WalMart years ago but then they stopped carrying them (IDK why). These little bottles pack a punch!!! I use the one labeled for "blood and milk" when I have blood to deal with, and definitely use the ones for "fat, grease, and oil" and "ketchup and sauces" a lot - they are super.
I don't know for sure about your mattress - you could try the Soilove or the Stain Devil for blood (I might try that SD first) and let them work, then gently blot with clean water and an absorbent cloth till the stain (hopefully) fades. Mattress stains are a pain - even simple liquids can leave a slight ring as someone else has mentioned.
Good luck with your stain removal!!
Blessings,
S.