What exactly does a silent investor do and how do I find them?

50-100K for a restaurant

A silent investor invests money into something w/o wanting anything to do with running said investment.Now, where to find them, I have no clue.

A silent investor is termed for a investor who invests large amoults of there money into your company either in shares or a direct payment of money, in return they are given a percentage of the proft you make or returns on how well the shares are doing but does not interfeace with how the company is runned.

A silent investor puts in ALL the capital, will let you run the business completely and will take NOT MORE than 40 % of your profits. Search the internet for risk capital.

How much do you need?

You are looking for an angel investor. Typically each major city will have a group of angels which is made up of individuals whom have run their own business. sometimes they have a private equity fund that they also run together or that assists them via "sidecar" investments.
But, in most cases, you will find that they expect to have a say in the business. But I would start by advertising in the paper. Don't hold your breath though...you need a solid written business plan and financial numbers.

Other answers have answered what they do, but how to find them? You don't. Any venture capitalist wants a say.

The only "silent partners" you'll ever find are friends and family...and in my experience their patience will run thin and won't stay silent for long.