How do I transfer music from my computer to my ipod touch?

Hi everyone, having a bit of trouble with my ipod. Ive just downloaded some music to my computer, and im trying to transfer it to my ipod touch. I saved the music into my normal music folder, then moved it into my "itunes folder" Then I tried moving the music files into the actual ipod icon on the left hand side that says "emmas ipod" but when i do, a window pops up saying "this device is not responding, or is not connected properly" but....it is. My ipod is connected to my laptop and has the charging signal up. Am i doing the right thing or is there a completely diffrent way to do it? Please hellp me as im at the end of my tether with this thing! Thanks Guys x