It helps to focus on how taut the strings feel when they're tuned. When you're tuning, pay attention to that. If they get feeling too taut, you're headed in the direction of tuning an octave too high and that will definitely snap the string. (It gets easier with practice, believe me!)
Well we all shine on--like the moon and the stars and the sun.
-- John Lennon
I always change one string at a time, beginning with the bottom (thickest) E string....this way you can tune the E string roughly to the A string, to make sure you don't overtighten....
Vic
"Sometimes the beauty of music can help us all find strength to deal with all the curves life can throw us." (D. Hodge.)
I just bought some elixers to put on my guitar and snapped two of the strings as I was putting them. Not the most expensive mistake I've ever made, but certainly the one I learned the most from.
http://www.daddariostrings.com/default.aspx
Choose Factory Tours and Videos from the side bar, a popup will open and then choose Product Demos. It will show a video of how to string a guitar.
Now I'm restringing an electric. But nor here can I get the old string of the bridge.... I've googled for some tutorials, but can't find anyone that has electric guitars.. Could anyone point me in the right direction?
"Trying is the first step towards failure." 
