Re: Working spouse
Note: L1 is the visa you get if you are on temporary assignment to the US office of your current employer. I don't know if it lets you apply for a green card - the rules change because they get exploited.
One thing you do need ex-pat contacts for is that nobody in any branch of the US govt (a land of immigrants) understands the systems for non-Americans. You will get frustrating conflicting different rules from different Govt. depts.
eg. You must get a driving license within 7days of moving to California, you need a SSN to apply for a driving licence, it takes 4 weeks to get a SSN. Well why don't you have a SSN from the state you moved from ? Because I didn't move from another state!
Don't get me started on the kafka-esque nature of the "you must surrender your out of state licence" but a UK licence isn't out-of-state, not is it a Californian license. The computer demands that the license must be Californian or out-of-state ... repeat....
It's the same with tax, visas, health-care, pensions etc etc
Even if you get hired by a $Bn global corporation who promise that their lawyers will sort everything out - don't expect them to do it right.