I couldn't live without my dehydrator. I use it for everything. Herbs, fruits, mushrooms, jerky, fruit leather, lots of stuff!!
American Harvest makes great dehydrators in lots of sizes and price ranges. Do yourself a favor and get a model that includes a fan. Some of the cheapest do not, but you must rotate trays regularly when drying if it doesn't. I prefer one that includes a temperature control as well. Delicate things like herbs and mushrooms need lower temps than things like jerky. You can get them round, square and rectangular, it's just a matter of space preference. Surprisingly enough, sporting goods stores like Bass Pro can sometimes have great prices, especially now because of hunting season.
Lots of dehydrators come with a basic guide and cookbook, but the Ball Blue Book of Preserving goes much more in depth, and gives ideas and recipes that go way beyond the starter guide that will come with your dehydrator. The book also covers canning, freezing and lots of other things.
I wish you all the best with your experiments, you'll be hooked in no time!!
Gale