How to Use SharPoint?

http://www.learnsharepointtrainingtutorial.net.in/sharepoint-stepbystep-part1.html

Hi,

Site, libraries and lists are the basic collaboration features of SharePoint. 

A site in SharePoint looks like any other web site. A site contains pages and a page can contain web parts for functionality. A site can be setup for a department, meeting, project or process.

Libraries are used to store documents and files. Metadata (fields) can be added to a library to attach to each file uploaded which makes it easier to categorize and search them.

Lists are used to store information and data. The information or data is store as metadata (fields) just like libraries. 

If you have installed the sharepoint on server then you can start to browse. 
If you have permission then you can create you portal. You can add forums, etc..,

Use of share point:
You can create the site and site collection to upload the documents, forum and easy to customize the page. The user permission can be given to the folders,etc.., The documents can be checked out and do the changes and check in back to the origin. The read, read-write, etc.. can be given.

I suggest you to go through this url:

http://www.sharepointhostingprovider.com/sharepoint-tutorials/ 
http://www.sharepointhosting.com/video_tutorials.html
http://sharepoint-tutorial.net/
http://www.fastsharepoint.com/

Here is a comprehensive reference for the usage of SharePoint. It includes information on the functionality and benefits of using SharePoint and has additional links to white papers and an evaluation guide.

http://sharepoint.microsoft.com/en-us/product/benefits/pages/default.aspx