Pitching to Investors
You need to start creating a list of possible investors for your film by who is going to benefit by its production. If you are preparing a project close to home you may be able to find local corporate sponsors who will put up financing for possible returns on the investment, product placement of their brand, or both. This is going to amount to local advertising and is not going to be substantial, but may get you started.
For raising money on a short film from an unproven director it may be best to look at professionals who are willing to put up a small amount of money. Doctors, lawyers, and other groups who work in professional circles that are very close to one another are known for pooling their money in investments, and this can be a great place to look.
The reality is that you need to know where you can get into, so try to put together your possible contacts. See who you will be able to get into a room with by seeing who you know, who they know, and starting from there. Here you will then want to create production binders with the information and budget you prepared for the film, your plans for film festivals and possible sale and distribution, and what their returns would be based on percentage in the case of sale. This should be written up in the form of a contract, but does not have to be notarized by a lawyer unless you have that resource easily available.
If you want investment from a group that will intend to broadcast or distribute it, such as a film studio or television company, you have a much more restrictive road ahead of you. First, it will be difficult to get into a pitching session for these outlets and they are not usually built for distribution of short films. Second, they will take a large amount of control over your project and you will be limited creatively.