Work of any kind requires an understanding of the appropriate tools for the job, and social media is no different. You can't pitch hay with a shovel, and you can't dig a ditch with a pitchfork. Here are some serving suggestions for a set of social media tools. The actual applications will change over time, because technology does that. But the basic functions should evolve a little more slowly.
In social media, as in life, listening is twice as important as speaking. Online, the tool for listening is a newsreader. This type of software allows you to understand the conversation going on out there, and the best newsreaders permit you to understand a little better what you're "hearing."
If you Google the phrase "grow bigger ears," you'll find a really quick way to start listening for free using some of the tools that I'm about to mention. (This gets a bit techy. If you feel twitchy about it, just skip this part for later. Throw in a bookmark or sticky note, or highlight it, and come back. It's okay.)
I recommend Google Reader. It's easy to use, has ways to roll through information quickly, supports the import and export of OPML (which is simply the bundle of all the feeds you've selected to follow), and has some powerful sharing features that make it more compelling to me than other readers.
What should you listen to? It depends on how you're intending to use the tool, but if you're part of a company in a certain space, here's a way to think ...