A bit more info
This guide will help you tidy up your desktop and make it more awesome or pretty depending on what you like.While there are other ways or sites for finding icons and wallpapers, I have only named the ones I use.
Adjsuting your screen resolution
you can adjust your screen resolution by right clicking on the desktop and clicking properties and then selecting settings,here you can change your color quality and screen resolution,the higher the resolution the better the graphics of the background and you can store more icons on your desktop.(Screen resolution depends on your graphics card and monitor ,you can test out the resolutions,but don't worry if your screen goes black or too big because the change is temporary and will revert back unless you accept it)
I don't recommend using very high screen resolutions simply because mostly you don't need that much space and some programs and games have difficulty adjusting to some resolutions...
Picking and using you desktop icons
For desktop icons you have a lot of sites, the site i use for most of my icons is IconArchive
once you choose your icons,i recommend you put them in a separate folder where you can find them easier.Now you right-click on the icon you want to change, go to properties and click change icon,then find the folder where you put your icon and select it. That's it for icons..
P.S. Not all icons can be changed especially some system files.Don't worry, your screen will be just as epic even if my computer isn't a cool icon
Selecting your desktop background
If you want HD wallpapers then you can go to hdwallpapers.in then select your screen resolution and find the wallpaper you like the most
For normal or hd wallpapers you can simply go to google images and enter: "wallpaper" + your screen resolution (for example: "1440x900" wallpapers or something specific like: "Nature 1440x900")
in this step i recommend you install "UX theme multi-patcher"
Then all you have to do is go to customise.org, select Xp themes and choose the one you like the most,there are also themes for windows programs such as winamp,Mozilla, etc...