The student population in Valdosta doesn't represent enough of the population to completely dictate when the most apartments are available in the entire city. However, you should remember that student cycles apply if you want to find an apartment close to the university. In that case, you still want to focus your apartment hunt on the early summer.
Remember that applying for an apartment isn't just about the landlord finding the best possible tenant, it is also about you finding the best possible landlord. If you get a bad feeling about a landlord, or about a building, don't be afraid to walk away. The temporary inconvenience of not having an apartment doesn't outweigh the problems that arise with bad or absentee landlords.
Many people in Valdosta rely on the local bus network to commute. If you're attending the University, the bus lines can get you from most parts of town to school in relatively short order. However, the city is also very easy to drive. The easily accessed Perimeter Road circles the entire city, and provides a quick way to get to most destinations.
The summers in Valdosta get extremely hot, and visiting the Splash Island water park is a good way to cool down. You can also take advantage of the weather by hitting the Stone Creek or Kinderlou golf courses. St. Augustine Road is home to a number of restaurants. The Wooden Nickel Pub has a relaxed, small town bar vibe.