Here's a good link for the nettles.
http://gentleworld.org/nettles-health-tonic-and-veganic-fertilizer/
In a nut shell, chop them down, put them in a trash can (with a lid), break them up to create more surface area, cover with unchlorinated water, and let sit with the lid on for a couple weeks. This is a FPE (fermented plan extract). Super easy to make, and very effective. Plants like nettles, comfrey, etc send roots down very deep and mine minerals and nutrients, which then accumulate in their leaves (bio-accumulators). We can then take these plants and use the nutrient/mineral rich leaves to nourish the plants we are growing.
As for the meals, I would recommend the following: Pick up some alfalfa meal, kelp meal, and if you can find it locally crab shell meal and neem seed meal. Also grab an all purpose organic fert like Espoma, or Down to Earth. You can add apx 3 cups *total* per cubic feet of those amendments. IOW, if you grab all 5 of those items you will use around a 1/2 cup of each one per cf. If you use a little more, or less it won't hurt as it is quite hard to "burn" a plant growing organically. You want to amend your plot with the compost and those meals a good 4 weeks or so before planting if you can. Once bud sites really start to fill in, scratch in some more of the same as a top dress, and cover with a bit of soil/compost. You can use your nettle tea from time to time as needed.