It depends on which route you want to go with most. If you want to focus on poetry and short stories, you would be better off submitting to literary magazines. The legitimate ones pay per word and getting accepted is like cat nip for agents (if you want to get into books later).
If you want to focus on non-fiction articles, then its an entirely different set of challenges. Some websites 'hire' writers for various topics (like eHow and Examiner), but they tend to pay very little and demand very specific material from their writers. Places like HubPages (that pay based on advertisement clicks) have more freedom, but making money is incredibly time consuming. You could have hundreds of articles working for you and still be making pennies each day.
So, depending on which route you feel more passionately about, pick the one you would rather spend most of your time with.