I am a beginner, and could anybody help me learn how to upload my iphone itunes music to my computer so i can get an iphone update?

Ok, i clicked the link you provided, then i clicked on store next to the apple icon. Then i get sent to a page that off to the left, says popular accessories, and off to the right, it says at the top, more stores, and underneath, it says store services, but i don't see anything that says authorize computer, or transfer, or nothing like that.

First of all Ana, i don't know which version that i have. Next, when i'm on my desktop, i right click the itunes icon, then i get sent to a screen that looks nothing like the icon bar in the previous response you gave me. When i open up itunes, this is what i see. Off to the left hand side it say playlists. It says 90's music, classical music, music videos, etc. Across the top, instead of what you sent me, with the apple icon, then itunes, etc. This is what it says across the top of my screen. Songs, albums, artists, genres, playlists, radio. And since i've got my phone plugged into my computer, there's a pop up that says there's an update for my phone. I want to update, but when i click update, it tells me that my itunes store purchases are going to be deleted, and i don't want to lose all of the music i PAID for. I don't know how to get to the screen that says itunes,file,edit,view,etc.