Deploying a SharePoint webpart

There are several ways to do it:

From Visual Studio 2008 [Condition: You have the source code]

1) In Visual Studio 2008, DEPLOY webpart solution
2) Go to local SharePoint, Site Actions -> Site Settings
3) Under the Site Collection Administration header, click "Go to top level site settings"

4) Under Galleries, click "Web Parts". You should see your web part listed there.
5) Under Site Collection Administration, click "Site collection features". Your web part should be Activated.
6) Add a new web part page, click Edit Page and then add the web part to the page.

Using CMD [Condition: You only have the wsp file]

1) Type cd C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\BIN
2) Then type stsadm -o addsolution -filename [insert filename]
This will add your solution (.wsp) into SharePoint
3) Launch SharePoint Central Administration.
4) Under Operations, click on Solution Management. You should see your webpart there.
5) Click on the web part, then click Deploy.