First. that outlet may be 30 amp, 120 volt, or 30 amp 240 volt. Please use a meter and CHECK it first..... (pays to be sure)
now, how to hook it up
On the house have an electrician install a proper Generator Transfer Box with a proper inlet... This inlet will normally be a 30 amp 4-wire 250 volt TWIST LOCK "plug" in a housing
now, you will need
A 30 amp RV power cord, Male plug, tinned leads on the other end (Bare wire)
One 30 amp twist-lock outlet matching the inlet (Must mate with inlet)
Hook up as follows
Green wire to green screw
Black wire to copper screws (Marked normally L-1 and L-2 and you connect this wire to BOTH of these screws)
White wire to Silver color screw (Marked W on many plug bodies)
And that is all there is to it.
If the outlet is 240 volt.. then there is somethign different.
DO NOT FORGET THE TRANSFER SWITCH BOX
You do NOT want to back feed the neighborhod or the mains.