I put in a sliding barn door earlier this year to cover the door opening in my master ensuite.
Its a pretty easy job. And I massively suck at anything handy. You can do it!
I got my stuff from Windsor Plywood. It was about $400 for the door and the track. The door I got was wider 34" x 80", made of wood with 4 frosted glass windows in it. Kind of like this.
If you're just looking for standard 30" x 80" or 32" x 80" keep checking the Home Depot or Lowes flyers. They are always on sale.
The main thing is getting the track mounted on studs. The door and hardware are really heavy.
The holes in the track probably wont line up with your studs, so you'll have to do 1 of 2 things.
1) Cut out the drywall above the opening, install wood backing, and then re-do the drywall. Then you can mount the track directly into the backing. Too much work.
2) Put a piece of nicely painted wood on top. Screw that into the studs, patch and paint the holes, then mount the track onto this thing. Like this.
If you go this route, make sure the wood you choose isn't too thick. The one I picked was so my door is a bit farther out than I'd like.
The rest is just measuring, and drilling.
Like I said, not a bad little DIY project!