[cr33pyguy]

Here's what I'd do:
Travel into the past, I don't know what sort of time period you're saying we'd travel back too, so I guess I'll assume 100 years. Now, what I do is I take some books I made with me, in these books, blueprints and facts. Things that will happen so that I can use them to my advantage, but more than anything it will be blueprints, modern computers, graphics cards, CPU's, modern cars, cameras, mobile phones etc. I would quickly become the richest man in the world whilst also having all the technology invented almost 100 years earlier, allowing humans to become more advanced faster whilst I make a fortune and live like a king. Everybody wins.

I watched a video about this. It was slightly more extreme, but the same basis.
here's a link to the TED talk: http://www.ted.com/talks/thomas_thwaites...om_scratch

basically he does as if he had to do it all himself - build the toaster, starting by getting iron and things all the way to the plastic casing. You'll have to see what happens for yourself.