Thanks for writing. I'd first test your soil and find out how acidic it is. Sometimes soil beneath large pines can be very acidic and other times it's fine.
If the pH isn't a problem, then there's nothing special you need to do --- just clear out the weeds and either rake up the pine needles for use as a mulch or till them into the soil as organic matter. If there are large pine roots in the soil you may need to dig them out or plant around them.
---Justin, Senior Garden Editor, BHG.com