Well...a linear curve isn't actually a "curve" at all. A linear curve is 0,25,50,75,100. If you look at a linear curve in your Throttle or Pitch Curve settings, you'll see that it's actually a straight line.
When I started asking questions about getting my 500e setup for a beginner (me, lol), several people here suggested the following:
Throttle Curve:
Normal Mode: 0,30,75,75,75
Stunt 1: flat curve 85,85,85,85,85
Stunt 2: flat curve 95,95,95,95,95
That normal mode curve will allow you to spool up the helicopter and then have the same throttle settings above mid stick. I can assure you, this really helped me because I was able to move the helicopter with the pitch of the blades. If you had a linear throttle curve, you would be able to move the helicopter with the throttle and pitch and this is quite difficult for beginners. I had a linear throttle curve, once, and it scared me very much. The flat curves really really make a difference.
Pitch Curve:
Normal Mode: 46,48,50,75,100
Stunt 1: linear 0,25,50,75,100
Stunt 2: linear 0,25,50,75,100
This "Normal Mode" curve will allow you to use the 75% throttle curve and be able to move the helicopter up and down with just the pitch of the blades. It's a very smooth movement. Also, the 46% and 48% pitch, at lower stick positions will allow you to set the helicopter down gently. Then, when you are ready for Stunt Mode, you will have the linear curve to give you your positive and negative pitch.
These are the settings that I started with and, honestly, these are the settings that I still use to this day. My 500 fly's very well with these settings and I'm getting more and more comfortable with each flight.
If you have a flight simulator....try out these settings and see what you think.
Now...these settings are merely a starting point. These settings may not work for each and every pilot. Feel free to make changes as you need them changed.
Good luck buddy