Converting a Single Family 7 Bed 3 Bath to a duplex.

I've just purchased my first Investment home with the intention to extend the parking space and convert the dwelling to a duplex where I'll live in one unit and rent out the second unit.  The end goal is to have have to have enough parking for a single vehicle per unit, to separate the water and electricity, and to convert the single family into a duplex. 

Can anyone recommend the professionals that are absolutely needed to accomplish these objectives and possibly and probably more importantly, some shared wisdom and advise.

Any feedback would appreciated.