Please look at my old thread geared for beginners.

http://www.rcuniverse.com/forum/m_4853740/tm.htm

Read through the first three links in that thread. Then ask any questions you might have. Don't get too involved in the "diesels are 50% stronger than glow", just buy an engine in the suggested size range.

I would suggest buying a built as diesel engine for your first. PAW or MVVS, though MVVS will pretty much only be found on Ebay. Buy model diesel fuel for you engine. Forget about homebrewing until you've burned up your first couple gallons.