There are several ways to make bulk product edits within the admin site:
From the Products Menu, click Bulk Update Pricing
On this page, store admins can edit variant names, SKU suffixes, prices, sale prices, inventory levels, and published status in bulk, rather than opening up individual products in Product Manager and changing them one at a time. For products with multiple variants, each variant will be displayed individually, so all variants can be modified at once.
To edit values, simply enter the desired values in the fields on the page and click the Update All button when finished. Note that the tab order is set on this page so admin users can simply hit the Tab key to move from one field to the next. If only interested in editing one field, use the Filters (see below) to disable the other fields and the Tab key will take you directly from one field that you wish to edit to the next, skipping the extras.
Filters
The 'Show Filters' button at the top of the page allows admin users to narrow down the results shown on the bulk update page. Uncheck any fields that you do not wish to edit in this session and they will be left out of the Tab order (see explanation above) to make editing faster. Choose an entity type from the dropdown list and all of those entities will be displayed, allowing you to select a specific group of products to work on.
At the Entity Level
To edit products at the entity level (meaning you can edit all products within a specific category, manufacturer, or department at once), start out at Organization -> Manage Categories.
Note that you can choose any of the entity types (Categories, Manufacturers, Departments, Distributors), however this manual page will use Categories as an example. Click on the name of the category you want to work on, then in the window that opens, go to the Products tab.
On this page, you can clone or nuke/delete products.
Clicking on 'Display Order' allows you to set the order that the products will be displayed in when a customer enters this category on your site.
Clicking on 'Inventory' allows you to set the inventory level for all these products.
Clicking on 'SE Fields' lets you customize the Search Engine fields for these products. These values are used to create the meta tags on your product pages. See this page for more information.
Clicking on 'Pricing' lets you change the Price, Sale Price, MSRP, and Cost fields for all of these products at one time. Remember that MSRP and Cost are not actually used on the site, these are for internal tracking purposes only.
Clicking on 'Download Files' allows you to change the download file names for any downloadable products in this category.