New to SATA

Hello!

I have this mobo:
http://usa.asus.com/products.aspx?l1=3&l2=12&l3=45&model=407&modelmenu=1

In the manual, it syays: 2x Serial ATA with RAID 0, 1 function

Now, I have been using IDE all my life, and I am just getting into SATA. I know it uses a differnt power connector, so I will get that. I went to newegg to see what SATA drives they have. They have Serial ATA150 drives and SATA 3.0Gb/s. I am going to guess that the 3.0gb one, I don't have, and only newer mobos have that. I ask that can if I use both Serial ATA150 drives and SATA 3.0Gb/s(the 3.0gb drive will just downgrade the speed and work?). If there is any more info I need to know about SATA, that would help me out! Also if you know any HDDs that have SATA that would work w/ my mobo would also help me out. 

Thanks! 

SATA2 is just a faster version of SATA. Both are faster than IDE. Any mobo capable of sata1 can use a sata1 or sata2 drive, just at slower speed.  Parallel-ATA is what most refer to as IDE.  Also, a large number of SATA drives have molex connecters, but also come with a power adapter and data cable.
Another note, if your windows/linux/etc install disk supports installing on SATA, reinstall on the SATA drive. (faster read/write speeds mean better performance) AND MAKE SURE TO ALWAYS ENABLE S.M.A.R.T. !!