new "chick" on the block here...

hello all, my name is amy; i am very new to the world of chickens. 1st off, let me tell u all i recently purchased my very own 1st home (aug 2011...) i have almost 4 acres of land with it; on it all ready growing were pecans, black walnuts, figs & grapes. My backyard is 80% fenced in; with 2 big male dogs in a pen & 2 smaler female house dogs in the house/yard. I recently purchased 18 chicks;; 12 of them came from tractor supply & 6 of them came from a farmers exchange store further down the road. --(3 of them were big, yellow ones, 9 of them are black w/some yellow on them & the last 6 are light brown/dark brown.)--  right now 17 of them are 7 weeks old.. 1 of the big yellow ones died all-ready   i dont know what i did wrong with this 1, as the others ones seem to be flourishing.. i was told they are all females,, alas.. i seem to have no male/rooster in my flock..  where do i buy one, what do i do.. right now, during the night, they all stay in a med. size dog crate in my computer room, but the smell...  not so wonderfull by the morning. during the daytime, they are set outside in a 5X5 fenced area, but, they will be flying VERY soon.. my boyfriend & my room-mate are building a pen as i type/speak... my question(s) is this;; what do i do now? where do i get a rooster, how many.. i want my chickens for there eggs only.., how long do i have to feed them there $$$ starter food from tractor supply? can they eat grits, rice, cleaned veggies, grass clippings, wheat straw..??? anything else?? i am sooo new/green to this all, i could cry   i just want to provide them with all they need;; the right food, the right males..ect...  any/all advice will help.. thank you all sooo much...    amy  cntry3778@yahoo.com