How do I transfer the 3500 songs on my ipod classic to my windows laptop?

I have 3500 songs on my ipod classic that I want to transfer from the ipod to a windows based laptop, and also an ipad. The laptop has about 1,000 songs. the ipad has about 1,900 songs. In each case, the laptop and the ipad have some of the same songs as the ipod, and some recently downloaded ones not on the ipod. How do I do this and not lose any music I've paid for?

KernJim