Patience, practice, and dedication are always the key to becoming outstanding in any endeavor. Same with the guitar and the slide. Luckily their are some tricks to making slide guitar easier once you have a little knowledge playing the guitar.
There are many different techniques to using a slide. But I will start with the most popular. Place the slide on your ring finger on your fret hand. Rest the slide on top of a guitar string over the neck, do not press down all the way to the neck. Pluck the string with the other hand and move your slide up and down the string. Voila! noise. To make a note you place the slide over the fret. Not in between. When you are fretting a note without a slide you press in between the frets which causes the string to come into contact with the fret. Thus you are actually playing the note on the fret. When you place the slide over the fret it acts as the fret causing the correct note to sound.
I would suggest tuning to an open tuning to start out. It makes playing slide a lot easier. Especially if you plan to play the blues. This way you can just bar all 6 strings on the fret and you have a chord. The 12 bar blues is one of the most common song structures. Learning the 12 bar blues is a good place to start and fairly simple. By just learning 3 easy chords you can play to thousands of popular songs. Add the minor penatonic scale to this and you are picking and grinning.
I would suggest listening to different slide artists to hear how much feeling a slide can add to a song. Dwayne Allman is probably my alltime favorite. But everyone has different tastes and their are a lot of really inspiring slide artists out there.
I Just wanted to keep this simple and I will post more experienced learning tools in the future as well as links to great slide sites. But above all HAVE FUN! You dont have to become a slide god overnight. This page was meant for total begginers, sorry if I bored anyone else............Slide On!!!.................Greg