In my point of view, so called 'great small business ideas' have to fit certain criteria
before they can be called great and are suitable for full time stay at home parents. Firstly and most importantly you must be able to fit them in and make them work around the commitments of your busy family life and secondly, they shouldn't require that you invest a small fortune to start them up.
I personally wanted to start a home business because I am a full time stay at home dad but I also wanted to still be able to contribute financially to my family. Many of the people I have met along the way who also have home businesses are also full time parents. Some of them are only able to find ten or twenty hours a week to spend on building their businesses while others are able to find more time. It all depends on individual circumstances.
I personally manage to spend around thirty hours a week and sometimes more on my business. My two children are three and six years old and go to nursery and school, which means that, I am able to work for at least three hours during the day. My wife works and because she likes to make sure that she spends some quality time with the children on a daily basis always takes the children to bed. This means that I can start working again around seven in the evening and I usually finish around eleven.
I try to resist the temptation to work on a weekend, which I must admit is sometimes difficult because I genuinely enjoy what I am doing. It's very important to take some time for the family and friends though and of course there are always jobs around the house that also need to be done. Rome wasn't built in a day but it was built!
As well as your business fitting in with your family life you should be able to get started quite cheaply. If you have access to a computer and an Internet connection you should be almost there. My business is a mix of affiliate and network marketing. Some of the programs I am involved in require a small monthly subscription but some are free. Also, you don't need to have a huge marketing budget either because there are lots of free and very cheap ways to promote your business.
It is up to me how much time I invest in my business and how much money I earn. At the end of the day I am my own boss and I call the shots.