You'll need hell of a lot of discipline when sitting in front of a computer for learning. Many people struggle with all the distractions that the internet (or the computer itself) offers... you know, watching cute cat videos on youtube, refreshing facebook/ twitter/ cf.net, browser games, online news, and so on. It's so bad a friend of mine hasn't been able to finish his doctoral thesis for four years; he's stalled because whenever he encounters some trouble he'll get into avoidance mode, distracting himself on the internet for several weeks nonstop. I tend to be the same way, so I'm lucky I have an outdoor physical labour job right now with no computer around, but I'm scared what'll happen when I return to college.
So learning online sitting at a computer is risky if you tend to be easily distracted. Be prepared for major self discipline struggles.