Having started as a skeptic I LOVE social media!
My favourite is twitter - I love the interaction with other people, it makes working on your own a lot more fun.
LinkedIn I only recently got to grips with - I signed up months ago but only in the last few weeks have I invested the time to get my profile sorted and connect with more people. I've also gained a couple of new clients via LI which is great.
Facebook I do have but it's my least favourite - you don't get the instant interaction of twitter and I just find it.... boring really. I love FB for personal stuff though.
I've got a YouTube video but it needs updating, it's on my to do list!
As for time, when I'm really busy I just pop on each a couple of times during the day but make more effort if it's quiet to devote some time to it.
Did I mention that I LOVE social media?

lol