All the clubs are always crowded after midnight. The scene does not get going until at least midnight or later. I would get some sleep before you head out! I suggest the girls not wear short skirts because the men like to reach up the skirt if it is accessible.
The drinks are expensive! I bought a Fanta(pop) and it cost me 4€, which is about $5.50.
The atmosphere is fun, but not all it's cracked up to be. I only went two times and I was there for 4.5 weeks. I would only recommend going once.