Purchasing a Duplex for Investment

[Michael Rodrigues]

Here's my situation: 

I'm 32, I own my own home, which is a 3 bedroom townhouse that I purchased so that I could eventually rent it out or sell for a profit.  So far I've got about 30k equity in the house. 

I'm looking to start investing in real estate.  I'm thinking about purchasing a multi-unit or duplex that I can rent out for cash flow.  Would you consider this a wise first-time investment (other than my primary residence?)  I would probably stay in my current home and purchase this multifamily solely as an investment.