ITA with the PP!
Have you checked out the book 'Confessions of an Organized Homemaker'? If your library doesn't have it, ask if they will do an inter-library loan for it. It's a free service, and then you have access to books from libraries across the country
GO GET IT RIGHT NOW!!!!!!
The only way I can get DH motivated to sort through clothes is a process:
1) I have to sort through my clothes. For this part to be effective, put your "donatation/yardsale/etc." box in plain view in your bedroom, preferably close to eye level, maybe on the bed.
2) Give DH a goal. Something as simple as "your drawer needs to close ... easily". Or "you have so many work shirts that you don't even wear the ones at the bottom of the drawer". Or "I need more rags, will you find some work shirts you are tired of?" Don't give a specific goal ("get rid of 10 shirts"), because you don't want to seem picky/anal.
As far as the other stuff you mentioned, I just keep my clothing down to what can easily fit in my drawers, and make sure to have enough to keep me clothed between each wash load
I expect the same from the other members of my family.
hmm... what did PP not mention? sheets? We have only 2 sets per season. 2 flannel sets, 2 regular sets. You really don't need more, do you? You just need a set to use while the other set is in the wash.
Also, if you don't have one already, you need a big box/bag, whatever that is specifically for give-away items. Have it in an easily accessible place (not the attic or somewhere like that). Make a personal goal (don't get crackin on your DH until you can give away lots of things yourself first), like 5 things a day. It can be something as little as a spoon that doesn't match your set, or a bib that is one too many. Just meet your quota each day, and you'll find that the decluttering becomes almost a fun game (one that you'll like the results of at the end of the day).
Also, put that baby in a backpack or sling, darn it! Having an infant is no excuse for not decluttering!