I have been playing electric bass guitar for four days now. I have self taught myself everything because my book on how to play bass did not help one bit. I can read internet tabs but not normal tabs. I can play a few simple songs like Runnin with the Devil, Louie Louie and Run To the Hills. I don't know how good but I know they sound like the songs enough for me to recongnize them. There are three controls. I have determined one is volume and the other is a mute and the third makes the strings sound a little different. Anyway, the main issue with me is that I am having a lot of trouble with my finger work. I would really like some advice on finger work and playing bass in general. It would greatly be appreciated. Please help me.

Here is a picture of my bass too.