Mushrooms–friend or foe?

Mushrooms–friend or foe?

I've got some wild mushrooms growing in my garden. I used to pull them out, but I've since read that mushrooms are usually beneficial in a garden. Apparently they aid in the decay of plant matter. But apparently sometimes they're not good. So I'd like to find out what kind of mushrooms I have so I can do some research on them, but I haven't had much luck Googling them. Anybody have any idea what these are? They start out white, and taller than they are wide, and then they "bloom" into this more brownish color and the heads get wider than they are tall. I'm in San Francisco. If they are bad, is there anything I can really do about them anyway?
Holdsworth House, Halifax, England

Holdsworth House, Halifax, England

Crazy Sunflowers

Crazy Sunflowers

My garden..

My garden..

Instead of questions today I come with photos

Instead of questions today I come with photos

I’m so excited!

I’m so excited!

Some pictures of my old college apartment

Some pictures of my old college apartment