If you're planning on camping in the Ohio area in the Spring/Summer time be prepared for the occassional rainstorm and flash flood. It's good to keep two extra tarp with you; one to put on the ground and one to put above your tent before you set it up. This will greatly decrease your chances of washing away durning these storms (and I've seen it happen). Also, you will want to treat your tent with seam sealer and a weather resistant coating. Even though most new tents come with weather resiting coatings, treating or re-treating your tent will increase its chances against the elements and its lifespan. Nowadays, campers bring along portable toilets which is a great comfort. But many counties in Ohio have water protection laws; so you'll want to be extra careful where and how you dispose of the waste.
There are also many poisonous spiders in the Ohio area such as the Brown Recluse. My best suggestion is to try and remeber what these highly poisonous spiders look like and keep pay attention to your surroundings. Try to keep as many of your belongings as possible in air and water tight containers. Always check and shake out your clothes and shoes before you put the on. A short handled broom comes in handy for sweeping out any unwanted 'guest'; this way you won't have to risk a bite even if it isn't poisonous. Stay aware of any new marks or rashes on the body. If you do notice any take a pen and draw a circle around the mark. If the lesion grows outside of the circle within three minutes, get help immediately. In any case, if you are worried, help should be notified if any strange marks appear.
Don't forget to pack the good old snake and bee bite kits.