RDS sizing and Implementation

hello,

I want to implement RDS with following concerns.

• - I have 50 users
• - I'm going to publish SQL related application
• - I want to publish that app locally and publicly 
• - I want to get print out from installed printer on client PC
• - I want to allow users to share his files from RDS

1. What is the sizing and How to do it ?
2. How to do Bandwidth calculation?
3. What is the Hardware requirement and How to select correct server?
4. What is right method of publishing RDS(all roles on same server or different servers)?

If anyone can help me to sort these out, very much appreciate it.