So, i intend to buy a http://tinyurl.com/latahlm next friday. If i build a deck using these cards are they recent enough for me to use at FNM? i'm not looking for "tournament" legal, just something i can casually play with people. i am not familiar with the rules to modern/standard as i have never played at a FNM before (but i want to once i get these cards to add to my collection). Any advice is appreciated :)

The Theros block is the most recent, and legal for all sanctioned formats.

Have fun!
-Dave

If the format is Standard (most likely), as long as you're not using any cards that are older than the Return to Ravnica set, you're legal for FNM.

Keep in mind that FNM is a tournament, albeit a very casual one. I make that point because you may want to, if you have the means to do so, go to the store a day or two earlier and purchase the box. That way you can go though all the cards, make a deck and maybe get some advice or play test a bit with people at the store before you actually play in the FNM.

Let us know how it goes and what kind of deck you built!

Another suggestion might be to not buy a whole box of Theros but to go to your LGS and pick up 1/3 box Theros, 1/3 box Born of the Gods, and 1/3 box Journey into Nyx so that you get a smattering of cards from the entire block. You could then look at the decks people were playing at the Pro Tour given that it was block constructed and was limited to only cards from the Theros block. Just google Pro Tour Journey into Nyx and it will come up. You can use their decks for some inspiration (note you likely won't have all the cards in the pro decks, but they're a point of departure to build toward as your collection grows).