Easy cash:
At the Lieutenant screen, type I LOVE HANSON (case sensitive) to get $50,000 in the safe.
It will not work if you already have more than $50,000, however.

More money for everyone: 
At the Lieutenant screen, press d + a + r + t to give $1000 to all gangs.

Money and Hoods Cheat:
Go to 'Run' in the Start Menu and type regedit. Now click through the following folders... 

(1)hkey_local_machine 
(2)Software 
(3)Hothouse 
(4)Gangsters 

At 'Default Money,' change 2710 to 207101FF for unlimited cash. 

At 'Default Hoods,' change A to FF to start with a ton of hoods.