#1
Just need to know some basics about improvising, what should I know to make it easier?
#2
I'll tell you what I did, I learned since I've been loving you by led zeppelin. The main parts are in D# and move all over the neck. It was the first time I ever was able to map out a song in key, then I sort of stopped playing the song exactly like it was written and played all over the place. Not sure if that's a good way to go about it, but it's what I did, good luck.
#3
Learn scales, develop your own chops, learn more scales, develop new chops, integrate them together, listen to others, learn more scales, learn more scales, practice, backing tracks, learn finger exercises, integrate them, learn arpeggios, integrate them, learn more scales, practice, practice, listen to improv. jam sessions (BET Jazz tends to do a bunch of these).
#4
get a picture of an extended scale in a certain key - Start with pentatonic - It will show you which notes are playable in that key and while you're learning it's good to always end your phrasing on the tonic note (root).

The scale changes with each key. For instance A - A# you just move your notes up one fret.