I am an adjunct instructor at a non on-line school (traditional/on-ground) as well as an adjunct for an online university. The key is to ensure that any online school you select is accredited by one of the accrediting US agencies. If it is not, I would not consider it because if down the road you plan to transfer any of those courses to a higher level program at another school, it is highly likely that they won't transfer if they came from an unaccredited institution. This site lists the accrediting agencies in the US and may be of help. Any online school should have this posted on their site or any recruiters or advisors should be MORE than willing to share this with you if they are reputable:
http://www.back2college.com/library/accreditfaq.htm
Being accredited means the agency has monitored them for quality, which is a good thing!
One other option to consider since you said you are near completion of a degree....find comparable courses that you need and transfer back to your home/original institution to complete it where you began. This may reduce the number of classes you need to finish rather than starting over. I did this with my Master's degree. I had begun it at a traditional university, but moved several hours away with just 4 classes left to finish. I went and found comparable courses by checking both school catalogs to find the descriptions of the courses I needed. If they were similar enough, I submitted them to my original school and they accepted them. I got this in writing and was able to complete my degree without starting over someplace else. Do be aware that most schools have a limit of how many credit hours you can transfer in.
Two of the classes I took to transfer back were from U of Phoenix Online. I will tell you that the convenience is great if you have a family and/or work. But the time commitment is still just as much as you would need if you took an on-ground class. Most online programs have flexibility when you can log on and work on your class, but most still have deadlines each week for assignments. This is like the online school where I teach now. We have a module each week and while students can log on 24/7 to read lectures, work on homework, etc., they still have two due dates within that week for work. Schools will give you a site to purchase your books. Journey Ed is a common one. You can also purchase used books online through a variety of sites, including Barnes & Noble or Amazon. You can also rent texts through chegg.com. Many of my students choose that site.
Some students miss the personal interaction that you get in a classroom, although most online courses have discussion threads where you converse with classmates each week. If you like that personal interaction, I recommend making sure the format of any program includes weekly discussions. My students love being able to connect with one another this way. They provide a lot of support and encouragement to each other this way. Many have said they would not enjoy the class as much if we didn't have the discussion thread assignments. Each week they have to make a post with their response and then respond to at least two others with solid comments (details, examples, and strong feedback).
If you choose online, I recommend setting aside scheduled work time that does not allow for interruptions just as you would any other course. This will ensure you can devote enough time to get things done. I work from home teaching online with two kids, and I have to schedule time where my husband knows not to bother me so I can get grading done without getting interrupted. It's amazing how much you can get done in an hour uninterrupted!
Good luck!