I won't post any links here since it would be to outside sources, but Lansky and Smith's both make good guided sharpening systems that don't cost a week or month's pay. The little 3 stone kits they sell would work just fine and they have more expensive, more inclusive sets as well of course. There is a very small learning curve but the stones are on rods so it ain't much. lol

A Lansky kit:


Smith's version:


They're essentially the same damn thing. lol Diamond stones will be easier to clean and typically cut faster than natural stones. Natural stones might actually be longer wearing than cheap diamond plates though, as the plates can shed diamonds during use.

If you want to learn how to free hand Smiths makes a nice three sided whetstone. Of course the learning curve is steeper, but your options increase exponentially.

Whetstones:


Diamond Plates:


Also, unless you're wanting mirror polished edges, 600 grit is fine for finishing the edge of a normal daily use knife. If you have something more collectible or like mirror edges then you'll need to go up to 1k or higher, but that totally isn't needed for a shaving sharp usable edge.

Just use Google to find the best prices as these are two of the biggest manufacturers of this type of stuff and will NOT be hard to find. lol If you live in the states and have a sporting goods or hardware store nearby I can almost guarantee you they will have one or the other company's sets. Where I live Lowe's has the Smith's, Academy Sports has the Lansky stuff.