Legit work at home jobs where you get paided for your performance such as Data Entry and more.

The majority of such "positions" are simply scams..
Why start an eBay business or similar.

I have a friend that does medical transcriptions from home... she works 12 hour days to try and make decent money when it's available. Other times she sits around with nothing to do. I once asked her about this for another friend and she said not to get into such a thing as the days of in home transcriptions are slowly coming to an end. That is as close to a real online job as I know of... and you can't just do a job like that without schooling and such.

As stated, most at home jobs are scams.

No such jobs (all scams).
THINK about why they don't exist. We could go on and on, but you should be able to figure it out.

There are very few that aren't scams, like Curlyben said.

My son is picking up extra money by selling his childhood toys (Star Wars stuff, D&D miniatures and books) on eBay. High school and college students need papers typed, so if you can do a good job with that, that might be a possible way of earning money. Most of the effort can be done via phone and computers/email/word processing.

You might want to ask at your library for this title (she gives some interesting suggestions) --

The Work at Home Sourcebook: Lynie Arden: 9780911781205: Amazon.com: Books