I've used zucchini, beets, even green beans. I blanched the beans first. Toss with seasoning while still wet. Chili works well, so does vinegar and salt. Dry til crunchy. They go through a super leathery stage before they hit crunchy, you just have to wait it out.
I got two identical ones at salvation army so I can stack the trays double tall - they were each about 5 or 6 bucks.
And now I'm kicking myself - I just remembered that I wanted a book "Food drying with an attitude" - and I had a barnes and noble gift card but I blew it on gifts for other people yesterday; I should have got myself that book!