I have an INSIDE secret on preparing sweet potatoes and here it goes:
Wash it well, and stick it in the Microwave for 4 mins. Whallllaaaa, that's my inside secret.
LoL, actually I'm a busy man, so this is the only way I prepare them. Very easy and not time consuming.
Also, you can bake them in the oven, they are just like normal potatoes in the way you can prepare them.
My 2cents
Mr.X