My little guy loves sweet potatoes. I found it is far cheaper to make them myself from whole yams than to buy them in the tiny packages already pureed.
I used to peel, steam, and puree the sweet potatoes.
WOW ... I was wasting my time. A lady @ my MOPS table clued me in:
1. Rinse sweet potatoes
2. Prick sweet potatoes with a fork
3. Bake in 350 degree oven for 60-80 minutes.
4. Cool for 20 minutes.
5. The skins peel right off.
6. Mash with a fork or potato masher*.
*One would likely want to puree with some water in a blender
for younger babies or for babies who dislike lumps or the stringiness I've found to be typical of sweet potatoes.