Very nice stuff, dragongirl! I love ickle baby sweaters. 
Mostly I’ll just ditto what Zebra said.
A neutral background will make your pictures look much more professional. I don’t know that you need to buy something. A white sheet could do the trick. We have a folding card table with a beige top that’s ideal.
For photographing small items, you definitely want to stand over what you’re photographing and point downward so you’re seeing them flat. Get up on a chair if you have to, or spread things out on the aforementioned sheet on the floor. For one thing, when you take the picture at an angle, it’s all foreshortened so it’s hard to see the true proportions of the piece. More importantly, in your pictures I notice that part of the item is in focus, but part of it is fuzzy. That’s because when you’re photographing things close up, the camera can only focus at one specific distance. You want the whole sweater at the same distance. If the bottom hem closer to you than the collar, either the hem or the collar will be in focus, and not both.
As for lighting, I’ve had very good luck just shooting inside at night with my camera’s flash. A lot of your pictures in sunlight seem to be overexposed.
I think it’s well worth it to take time to arrange the items a little artistically. It’s a little fussy, I know, but you’re creating a record of these that will last a long time and be showed off to a lot of people. The picture of the white blanket draped over the chair, for example, is much more interesting than if it was just laid out flat. You get a sense of the drape of the fabric, and the different shadows bring out detail and texture. And like elbows said, take lots of pictures. You have a digital camera, so you can just trash whatever you don’t like. Try it from different angles, play with the lighting, rearrange the item . . . Working with cheap camera, some shots will end up looking awful, but you may surprise yourself by snapping some really nice photos.
And don’t be afraid to show multiple pictures of the same project! You can have a very clinical shot where the item is all spread out prefectly flat, and you can really see how the garment is pieced together, and an artsy one where the arms are arranged in a more natural posture, a closeup shot to show the detail in the hood, etc.
Be sure that as you’re framing the shot, you can see the whole item (except in closeups, of course). If you end up with too much extra space around the edges, it’s easy to crop out. And while you’re cropping, get familiar with your photo program, so you can tweak the color, contrast and brightness of your picture. Often times can take a kind of cruddy looking original, make a few tweaks, and get a much better iimage. That’s where a lot of the skill in digital photography lies.