There are a lot of good reasons to consider getting an online degree, however if decide that you want to get one there are a lot of things to consider. The number one consideration is do you really want to get a degree. Most people would like to have one but that really isn't enough, getting an online degree is a lot of work and requires a lot of motivation. Once you have decided that you want to attend an online university you will have a number of other decisions to make. These decisions can seem overwhelming at first but if you make them in a rational order they will pretty much sort themselves out.
The first decision that you are going to need to make in choosing an online university is what you want to study. This may or may not narrow down your choices. Some subjects like business are offered online at almost every university while others you may have to really search to find a school that offers them. In general subjects that would appeal to a mid career professional tend to be more widely available. Masters degrees are usually easier to find than bachelors degrees and professional degrees tend to be more widely available than liberal arts degrees. Online universities primarily target people who are already working and need to upgrade academically for career advancement.
The next decision that you will need to make is how you want to learn, there are a lot of options here. Some offer courses that are completely online, others will require you to do some of the work on paper and mail it in. Some courses require interaction with the professor and your classmates while others are aimed at individual learners and have no interaction. There is no one way that is better than the others you will need to assess how you prefer to learn and choose a course accordingly. You will also want to decide whether you want a self paced course or a course than runs on the semester system. A self paced course gives you a time limit, usually six months and you can work through the course at your own pace, a semester course will require you to submit assignments at specific times. Again this is a matter of personal preference.
Once you have decided on what you want to study and how you want to study you should have your list of options which may be quite large or very small depending on how you decided the previous two items. The next factor is going to be cost, there is a huge variation in cost between schools. Unfortunately education is one of those situations in which you don't necessarily get what you paid for. There are some very good schools that are very inexpensive and there are some very bad ones that are very expensive. In almost all cases the best value will be had at your local state university. However if they don't offer the program you want you are going to have to do some pretty serious comparison shopping.