The proper method of finding an investor is to first define what kind of investor you want including the money you need/want, develop a package to present to candidates, likely with a valuation of the business and prospective business plan, and then a marketing plan to reach the kind of investor you want.
The kind of investor could (generally) be 1) hands off, money only; 2) hands on, perhaps with specific skills, and with various sums of money, 3) venture capital, where they take the primary reigns of decision making, or 4) other company buying in/partnering where assets or systems/talents can be shared or no.
The package, a prospectus, is developed to put a reasonable best foot forward, just as though you were going to the bank. The valuation can be done professionally by someone like a business broker or by researching the Internet, though Internet information can be scattered and faulty. The valuation is typically done based on cash flows for the last three years and value of furniture, fixtures, equipment, inventory, perhaps a website. The business plan would include the financial and verbal description of what is expected to happen over 3 – 5 years based on current state, influx of their money, and includes marketing, products/services, personnel, operations, etc. There is also a description of how the investor participates and is rewarded, share of the annual income, wages, bonuses, etc.
Depending on the size and expectations this package can be five pages or fifty. Remember you are trying to WOW someone.
After it is written, you develop the marketing plan to capturing the investor.
