I have a mobile home that I want to rewire with up to date specs and such. Im not sure what kind of trailer connecter is used most commonly today, and what kind of circuit breaker box Ill need to use and important safety codes or instructions I should know. Im looking for either first hand knowledge, or for a website or somewhere I can get the information.

Which Trailer connector?
I was was to do this, I would Pull All Number 12 if possible, may be some switch circuits up to lights may be difficult if wall not removed, then I would leave existing 14 if that's what's there, I would replace all the Aluminum I could.
I would use a Panel Rated for Your Service
(100,150 amps, ) It would be a Panel to allow more Breakers especially if tandem or double breakers are used.
Then Might as well install interconnected smokes in and out of all sleeping areas.
GFI's in Kitchen and Bath.

I would check with the Authority having Jurisdiction.

I'm not being flippant, but I suggest you call several licensed electricians and get bids that include filing for permits and inspections.