Whats the best way to install the apps I purchased for my Ipod to my new Ipad?

When you sync your iPad to the same computer as your iPod, they will all get transferred. You can have several different devices synced to the same library (and thereby share the contents of that library - all, some or none of it), but you can only sync a device to one library.

you can also download from the app store on the ipad and you wont be charged agian

For those apps that you purchased on iPod, you can run select iTunes File menu->"Transfer purchases from iPod", then sync to your iPad.

Go to the app store and purchase them again, it will allow you to get it for free since you have already purchased it previously. Or just put your apps on your iPad through iTunes.