It all depends on how dull you let your blades get.
I use oil stones. Specifically a Norton 313 plus a soft and a hard Arkansas stone when doing dull knives for other people.

When doing my own knives I just spend a few minutes with a Dexter Russell Oval Diamond steel and a Victorinox fine cut steel Both are 12".


Both methods are very easy with about 15 minutes of practice. The Norton kits come with an angle guide.
If you're going to get some stones I suggest getting an oil stone kit from
http://www.sharpeningsupplies.com/Oil-Stone-and-Arkansas-Stone-Kits-C128.aspxThey have really good prices and the best selection. They offer bundles for people who need to buy a whole kit. You can get fine results with synthetic stones, the natural Arkansas type are all beyond fine grit and overkill for most people. I'd definitely suggest getting a Norton 313 since every butcher shop in the US has one for shop use.
Longer stones are easier to use.
You will need a honing steel to finish any sharpening done on stones as well as keep your edges dressed between sharpenings. I do not suggest ceramic unless you're already good at using one.