Here's what I can offer...
I have a dirty, shameful confession to make: I almost never change the strings on my electrics until one of them breaks, and then I'll put a whole new set on.
It's not a budget contstraint, or a newbie thing. I've been playing for 20 years, and I've done a decent amount of session work, and I consider myself a fairly experienced guitarist. I have just found that I prefer the sound of dead strings for recording.
It's funny, but like pchorman just said, I almost always wash my hands right before I begin playing. But then.... once I'm set up to start tracking, I rub my left fingertips on my forhead to pick up the oil, and it's just awesome the way my fingertips glide around! And then when I case up my guitar I wipe the strings down.
Now, steel string acoustic and bass are a completey different story. New strings are a must. (Although I must again confess that I've recorded a couple great steel string tracks with dead strings, and kept them even on the final mix because they sounded just fine. *gasp* )
And don't even get me started about nylon strings. Of all guitars, nylon stings are my favorite. I think they are the most expressive variation of the instrument, but I loathe the freakin' strings!! They sound best w/ new strings, so you stick a new set on, and then they stretch and stretch...and stretch........and stretch...........and stretch. And then, finally they settle in.....and they're dead. AAAaarrrgghh!!
Now that you know my secret, I hope you'll still respect me.
Aaron
http://www.aaroncheney.com