Breeding Help

Need help!  I'm a beginner and have two show heifer calves in the barn.  First question, at what age should I breed them?  And secondly, how do I know when they are in heat.  Any information for beginners is greatly appreciated! 

Also, how much should I be feeding them per day in order for them to gain healthily to ensure they're good cows?    Thanks. 

What breed are they?
What age?
What is their current weight?
What are you feeding currently?

You need to decide what your goals and needs are first off.  Two heifers ain't gonna make you a large profit either way you go.  Are you going to be able to expand, are expenses going to keep you on a tight management basis? If like most you expand off of increase in the herd,  tend to be a lot more on your own timetable and less on what everyone else does.  Letting a heifer calve as a 2 year old makes payday farther off but it will probably add 2 to 4 calves on the back end of the cows life. This isn't a deal where you can afford losing a cow just to have her calve at xx age.
  Stay away from the hot bull of the moment,  study pedigree's and make sound decisions on what to do,  and don't be afraid of taking a long look at the show ring as a learning school as well as a winning thing.