I may be looking for capital myself in a few months. Your choices are pretty much as you have outlined them.
-Line of credit - has to be secured with assets
-SBA guaranteed - tremendously invasive and intangible assets (skills and past record) are important
-Angel investors - best way to go, but you really have to sell them on your business
-selling shares - friends and family again. With this choice, they are not only sharing risk, but potential gain too.
-venture capitalists - they will examine your business plan very closely, which is an advantage similar to the mentor you probably should have. They will probably make more from your business than you will but will not be interested unless they can flip their shares for a good multiple in 5 to 7 years. In addition, your business needs to be proprietary and not easily copied. If you are interested in an ongoing business that you control, vc is probably not the way to go.
Here is one final option if your needs are less than $25,000 (mine are 20 to 40 times that), prosper.com offers unsecured loans from individuals in an eBay sort of way. Very unique! You must repay in three years.
I'm a long way from determining how much I will need. I might be able to swing it myself, but don't want to put all my assets at risk. I have pretty good odds of raising what I need from friends and family and some with networking.