In addition to the Creation Kit tools there is a simple and easy way for mod authors to upload their creations to Steam where they can be shared.
"The difficult part, of course, is creating your mod. To get started modding, install the Creation Kit – free through Steam to all Skyrim owners – from the Tools section of your Steam Library.
When you’re ready to share your work with the world, simply choose “Upload plugin and archive to Steam” from the File menu within the Creation Kit. Here you’ll be prompted to choose a name for your mod, as well as any description, content tags and thumbnails. The Creation Kit will notify you once the mod has successfully been uploaded to Steam."
Be sure to check out the content that has been submitted so far.
We are talking about it HERE. (Looks like there is a good video tutorials in this thread)
Also check out the free DLC Hi res texture pack.