How do I get the songs I've purchased from the itunes store onto a new itunes library?

I just downloaded itunes, and I go into my itunes account and look at purchase history to see all of the songs I've downloaded before. So how do I get those onto my new library?How do I get the songs I've purchased from the itunes store onto a new itunes library?
If you have an iPod, then put your songs onto the iPod. Then, connect your iPod to the new computer and once it shows up on iTunes, go to File and then click Transfer Purchases From iPod.How do I get the songs I've purchased from the itunes store onto a new itunes library?
i get them free so i a not sure

carolina skiff