In the developer section of umbraco v4 you can find the packages tree. There you’ll be able to install, remove and create packages.
You can install them from the Umbraco package repository
Or you can choose a local package file from you machine
There are some top umbraco packages out there, this is a small list of 5 umbraco package you must know.
Creative Website Starter (CWS)
CWS is an entire site implementation in umbraco aimed at helping new users learn umbraco.
The code is heavily commented to help understand what’s going on.
So if you are new to umbraco and you want to examine an example site, install cws.
ImageGen provides a fast and simple way to dynamically resize images and generate text graphics on your web site.
This is great to make sure content editors don’t mess up the site by uploading images that are to big.
Ever wanted to upload multiple files to the media section of umbraco. With this package (that won the cg08 package coding contest) you can.
UmbImport helps you import content or members from any datasource into Umbraco.
Xsltsearch is a plug and play search engine for your umbraco site.
You can have a search up and running in a couple of minutes, it’s easy to install and very flexible.