How to put pictures on my Iphone 3?

Yeah I know, my phone sucks but I want to set a wallpaper but I want to download my own picture. Or like from google. How?

Make sure you have internet connection on your iPhone - via Wi-Fi or a 3g sim card

Connect to safari on your iPhone - google "iPhone 3G wallpapers"

Find the image you like
1) Hold down on the image with your finger and a save option should pop up
2) Screenshot image by pressing both home and power button at same time

I not sure if your iPhone can do this, but go to the image you want to use as wallpaper and touch and hold it until it says "save image" then go to the Photos app and select the picture and select the arrow in a box button and you can set it as a wallpaper.