I need to see if this possible. I would like to make a wireless transmiiter/receiver and here is what I need it to do. The setup will have 3 buttons. Button A pressed will turn on machine A. Button B pressed will turn on machine B and when Button C is pressed it will turn both machine A and B on at the same time. Also i would need to have a delay for turning on of 3 seconds as an option. The machines will be about 300 feet from transmitter and about 200 feet across from each other. How would I go about achieving my goal. Would relays be needed. Are there any sample programs or libraries similar to my project. Thank you in advance for any assistance.
As I see it, range is going to be your biggest problem. You need to choose a wireless communication mechanism which has adequate range in your environment - which we don't know anything about. That need to cover 300 feet rules out a lot of the cheaper/simpler options.
I would say to use simple 433MHz Transmiter/ receiver, but for the distances you are talking about, I would suggest using Xbees. The coding for the 3 buttons is simple, but setting up the Xbees is where things get confusing. So that you'll need to do some research on. Heck, just look for a YouTube tutorial, there are tons.
If your completely new to Arduino or coding in general, then I suggest you start with the first arduino example and go from there. You can't really go any further without knowing the basics first. So start with those examples and put together a simple code that communicates between 2 Arduinos via Serial communication.