If you are an aspiring, practicing or city-based farmer, then you need to look out for iKilimo. iKilimo is the information mobile reference tool for all farmers that Avallain, the company behind it, says will be provide fresh and easy information to farmers on projects that they are working on and also allows them to share ideas, expertise from animal and crop husbandry, and information on how you can make the most of farm products as well as by-products.
If you want plans on a Green-House, you also need to check out these guys on Green House farming on Facebook.