Help me get the right visa to stay with my boyfriend and work too!!!

Yes, we did that.  But you will need to apply from the US, so your partner will either need to give your their birth certificate, a certified copy of their passport or if he can stay in the US the whole time then you can send his actual passport in. 

So I come to the US...we get married, then if he is with me, we apply for my spousal visa in the US (where we have to send in his passport with my application???) About how long does getting the spousal visa take? (we would be applying to the LA consulate)
Since he can only come over for 3 months as a visitor. Is there a way to extend his 3 month visitor visa if he is my fiance?

So I come to the US...we get married, then if he is with me, we apply for my spousal visa in the US (where we have to send in his passport with my application???)

Yep.  Easy peasy.

About how long does getting the spousal visa take? (we would be applying to the LA consulate)

There have been some fast turnaround times lately, so it could be within a few days, up to a couple of weeks.  If you want to ensure that you get it in a few days, you can always hire a courier.

Since he can only come over for 3 months as a visitor. Is there a way to extend his 3 month visitor visa if he is my fiance?

No.  But he's not likely to need longer than 3 months, your visa won't take that long, provided your application is complete and everything is straightforward.