At least in my profession, you can not look at it as an alternative to daycare. This is especially true with young children. Just because my office happens to be in my spare bedroom, does not mean that I still do not have to work 40 hours a week, and I do have a quota that must be met (I am on my morning break right now). Another piece of advice, Make sure you are working for an established company. There are many "fly by night" companies out there. The company I work for has been in business for 20 years, they have established contracts, they pay all of expenses, provide computer and material, etc. and they carry liability on me.
Good luck!
Billing would not be a problem. The fun is trying to find who is legit. and who is not.