Love & Renovations
I recommend starting here if you are new to wallpaper. It's a full tutorial, with all the details you need. Then, read on for a few more quick tips.
Before you install one length of wallpaper, line up and cut the NEXT one on the floor. It's much easier than lining it up on the wall!
For your first job, buy at least one more roll than you think you'll need. It allows for mistakes, and you'll always be surprised by how much waste there is!
If you have textured walls, you can still wallpaper! Just skip the peel & stick kind and make sure to choose a high-quality paper.
If you're going around a full room, be sure to start in an inconspicuous corner - the pattern may not line up when you get all the way around the room!
Remind yourself that it's not going to be perfect, there will be mistakes, and that's okay! Embrace a couple of flaws and remind yourself that no one will notice.