If you are looking for an overview on obtaining a loan, I wrote a post about loans Here ...
But I'd like to make a quick point about your construction loan.
If you need a construction loan and mortgage, it is essential you speak with your modular home dealer, and financial institution before you sign anything. I suggest you consider using a lender that your dealer/builder works with to avoid surprises. Otherwise, it's imperative that you check with your choice of lender to be sure they are able to work around your builders draw schedule. If the bank will not budge, then you need to see if the dealer and/or builder can work the lenders payment requirements.
If neither can reach an agreement, you may have to find a new lending institution, or modular dealer.
If you have any questions, please feel free to comment.
(We used Key Modular Homes as our modular home dealer. They are more than helpful in helping their customers secure a loan.)