I haven't been to (or heard of) Liberty Bell. My recommendation if you want to get into road course, is start with HPDE. NASA Northeast does HPDE in Millville, NJ which is relatively close to Douglassville as far as tracks go. They also do Pocono Raceway.
If you do HPDE, you'll have an instructor in the car (and more importantly IMO, so will everyone else). It keeps everything much safer but there are no speed limits. You also learn a ton, I'd recommend it to anybody and it is well worth the cost.
Before you go on any road course, make sure you flush out the DOT3 brake fluid completely and replace with DOT4. Boiled brake fluid is the quickest way to ruin your day.