Blogging - This is frankly not the top of my list, because it generates the least cash for me. I do receive some cash, as well as some things to review or promote. Unfortunately, I don't have a lot of info to help you get started with this. The companies I work with for these are relationships I've been in for years, and my understanding is that they approach the blogs they want to work with.
Test Scoring - I originally got started with test scoring (my title is 'Reader,' and I read the essay portion of standardized tests) by working at a live testing center that was near where I lived at the time. When the position was phased out there, the gossip mill sent many of us to Pearson Assessments. I don't recall the exact requirements, but I believe they require a degree, as well as teaching or scoring experience. This is a very part-time position for me, as most scoring of projects (at least the ones I am qualified for) are for just a few months of spring or early summer.
Dog Walking - Hey, this is my story, and the neighbor's dog is a part of it :) I walk the little tyke around the neighborhood twice a day from Monday - Friday. It's part of my list of consistent income, and also gets me some exercise and fresh air. A job that doesn't keep me chained to my computer is a very good thing.
Close To My Heart - I just started in the fall as an independent consultant with Close To My Heart (CTMH). CTMH is primary a scrapbooking and card-making company, with lots of papercrafting supplies, as well as some jewelry making stuff, and frames and things that you can customize for home decor. While I'm really enjoying doing workshops in my home, and making cards and things for samples in my spare time, this is not my biggest source of income. If I devoted the same time to it, it certainly could generate more money for me, but that's not my priority with this venture. There is a start-up cost to this business, but you get a huge kit of stuff in exchange for your investment.