Here's a rough estimate, though these numbers may vary widely:
Gross income: $150k
Fed Income Tax: 20% $ 30k (Depends on dependents, etc.)
Soc Sec and Med Tax: 10% $ 15k (Depends on dependents, etc.)
State Income Tax: 10% $ 15k (Depends on dependents, etc.)
Medical Insurance: $ 2k (Varies widely based on coverage, etc.)
Life, disability, etc: $ 2k (Again varies widely, but plan on something)
Takehome: $ 86k
My estimates may be way off (I live in Texas, not California), but this should be something to start with.
As far as cost of rent, etc., try looking on zillow.com, realtor.com or some other rent/home sales website in the specific area you're thinking you'd live. There's no way to estimate that based on "Silicon Valley".