Welcome Adam,
I'm in the Inland Empire, not to far from you. I also have a computer background, mostly in software support and teaching.
I started my real estate investing as a birddog for a local Realtor. It was a good introduction into investing. Finding motivated sellers will be the basis of your business. If you become successful as a birddog, those skills will serve you will in your future real estate investing strategies.
There are a number of ways to find motivated sellers besides the MLS. Some methods will be better in some areas over others. What determines a good method is your maket area or "farm". Get to know as much as you can about your farm before you start marketing in that farm.
In the begining the best method of finding motivated sellers will involve testing. It could be signs, postcards, letters, flyers, door hangers, online advertising, etc. Determine which one(s) will work in your specific farm. Then you must be consistent with your advertising to see results.
Search through BiggerPockets, you will find a wealth of information on birddogging and advertising. And here's to your success in investing.
Loretta