SharePoint 2010 - Deploy a Custom WebPart

Build a release version of your web part to create a .WSP file

Copy the WSP file to the target server

On the target machine, ensure you have correct SPShellAdmin permissions for the Sharepoint Management PowerShell:

Add-SPShellAdmin –UserName DOMAIN\YOUR_USER

As per this excellent article:

- Add-SPSolution c:\your.WSP

- Install-SPSolution –Identity your.WSP –WebApplication http://yourSPInstance  -GACDeployment

- Go to the Site Settings page, choose the Web Parts gallery and Add a New Web Part. Your custom web part should be there and you can Edit it to set the title, description and group.

To do an update later if you've amended your web part code:

Update-SPSolution -Identity your.WSP -LiteralPath c:\your.wsp -GACDeployment