Hi B.,
One thing I remember as a child was being told that I wasn't doing something right or it wasn't good enough. That made me not even want to try. As I grew older, the mantra of "If you can't do it right, don't do it at all" became mine. Once I found Flylady, I remembered how it made me feel when my mom would redo something I'd done to try to help. It made me feel worthless and sad.
I've slowly been trying to get rid of my perfectionisms and have my 6yo son mop the floors (he misses the corners occasionally and I show him how to get them clean while praising the job he's already done), both 4 & 6 yo boys clean the bathroom counters, sink, mirrors and outside the toilet. (There are streaks on my mirrors, but there are huge smiles on their faces -- that's better than a streak-free mirror any day.) They clean off the table and wash it, empty the dishwasher and put away the things they can reach. They dust (each has their own duster) and vacuum, put groceries away, etc. They fold the towels, even empty the dryer into the basket and bring it upstairs. They put away their own clothes as well. They make their beds -- just a comforter on top of a sheet. It's not perfect, but it's done and they feel great about having done it.
Check out www.housefairy.org for more ideas, too. She's great and takes the stress out of getting kids to clean their rooms and makes it fun. Also, Flylady.net has student Control Journals to help kids with routines. I adjusted it and found pictures to put on it for both as my 6yo is just starting to read and my 4yo isn't reading yet. It's great 'cuz I just have to tell them they need to do their list...not every thing on the list. :) If you want a copy of the picture version I made, just let me know.
Good luck and most of all, make it a fun learning experience for both of you.