Recognize that while some reporters are transparent (if it's a human interest story even likely sympathetic) there's no way to know in advance the angle the reporter will take--even when you try to "seed" the story. Know this going in.
Before you make any calls, do your due diligence. Research his/her previous stories. Find out what they cover, what their style is, and their specific areas of interest. Be prepared to commend (but not too lavishly) the reporter on his/her reporting. That may not be necessary but even a little due diligence will help you prepare your messaging and put the reporter "on notice" that you're aware of his/her beat and coverage.
Having done that, set up a very informal conversation (either by phone or in person) during which you can seed your story. Answer honestly any questions the reporter may have; offer answers under the guise of your desire "to make sure his/her visit is as productive as possible." During that conversation, mention certain organizational success stories--testimonials of people who have benefited from their participation in/association with your organization. Do this to positively predispose the reporter. Offer an exclusive: Reporters are always interested in exclusives; this is a influential concession on your part.
If and when the reporter comes to your organization or your event, plan in advance with whom you're going to connect the reporter. Connect the reporter with the people whose success stories you related during the previous conversation I recommended (above).
Be sure you've advised those people in advance that the reporter may speak with them. Make sure you're briefed those people with the key organizational messages you want to communicate. This is to ensure that everyone's speaking from the same sheet and that you're managing the messages. This is hugely important: Reporters are trained to look for inconsistencies and then build their stories on those inconsistencies.
Don't be too eager for coverage but also don't be too suspicious. Both extremes can be interpreted as warning signs for an underlying story. Be transparent, be welcoming, be genuine. Play out the best stories in conversation and say, "you'll really want to meet these people for yourself" or "to really understand how
yourself." That's a little tease which validates the reporter's initial interest.
Follow these simple steps and soon you too will be a media maven.