How to get music from my computer to iphone?

So I downloaded music to my computer (legally) and I got it on my itunes on my computer. But how to do get it on my phone? Thank you!

Added (1). Also, all the songs I have bought are in my icould but not the ones I downloaded!

FORGOT IPHONE PASSWORD

Someone in my form changed the password then forgot it, I have 2 months of work on it so restoring it isn't an option… Help!

What is the best waterproof iphone 4 case?

I'm looking for a waterproof-lifeproof iphone 4 case for my iphone 4. I want to be able to take pictures underwater with my iphone, so i want a case that can go underwater for a while. (NOT A CASE THAT CAN JUST HAVE WATER SPILLED ON IT) i also don't want to spend a ton of money on it either.

Selling 2 brand new IPHONE 4 cases?

I have 2 practically brand new iPhone 4 cases. One of them I've had for 17 months. That one is gray and rubber. It has a NIGHTMARE BEFORE CHRISTMAS logo on the back. Looks like its never been used! I WILL SELL THAT FOR 10$. The second one it a DOMO hard plastic case. I had it since May. Has a slight crack over the hole for the camera. ( not noticeable at all ) I WILL SELL FOR 5$.

BUYERS… PHOTOS WILL BE POSTED TO SARAH RUTH EVANS ACCOUNT ON FACEBOOK AT 8 OR 9 PM

REASON WHY I'm SELLING!

well I just broke my iPhone 4.So I sold it to Gazelle.com!

Notes keep disappearing on my iPhone 4?

I've never had this problem until recently. But every time I use the Notes app, my note will disappear in a few days. This is SUPER annoying because I keep up with my work schedule using notes. Is anybody else having this problem? How do I fix it?

How to find out how much music i have on my iphone?

I already know how to find out how many songs I have, but i would like to know how much time in music I have? So I know I have 253 songs but i would like to know how many hours and minutes that is in playing time. I know it probably sounds confusing but please help me out!

Is it possible to put navigation in a classic?

I have a 1966 mustang fastback and would like to add hidden in the dash a touch screen navigation with satellite and sync for my iPod and IPhone. I want to hide it to keep it looking classic when I'm not driving it then Once I'm cruising I can listen to my own music. Is it possible with this older style of course I would have to and another antenna. But is it possible thanks. I need the nav to get me back home it will be restored in las vegas and I need the nav to get me back to cali.