I am certainly no expert! However, I can give you a little guidance. I recommend starting with something like the brown lentils you can get from your local grocery store. I just do an overnight soak. Most people then put the soaked seeds in a tray with some sort of mesh on the bottom or, in my case, I have a solid tray with SMALL holes drilled in one end for drainage. The idea is to have the seeds in about a 1/2 inch thick layer to help maintain some moistness so the seeds don't dry out completely. Then, 2 or 3 times a day, flood the tray and let it drain out. You will have to figure out what works for you according to how humid or dry your area is. The lentils, I like to feed as pretty small sprouts which only takes a couple of days. You are watching out for things like mold or bad smells. Good flats will smell like cucumbers or have a nice, earthy smell.
Other seeds I have tried (I listed above also) are PlotSpike Oats (don't do these!), Barley, and Winter Wheat Berries. I have just found some Triple Cleaned Oats at my local grain bins I hope to try soon.