storage and dates

[brokenneckblues]

I was wondering about proper storage of wines and how to know when is the best time to open them up (when you're thirsty?). I've seen most collection laying on their side and heard that the bottles should occasionaly be rotated. Do diffrent wines differ in storage practices? I mainly keep cabernet but have a few bottles of shiraz, merlot, and pinot. Most are California wines under $20 and dates range from 1998-2005. Should I bother saving them till a certain date or just open them whenever I feel like it?
Thanks!