Rapid Streams Name-Dropper is a free Windows utility that lets you drag-and-drop a new file name to files you'd like to rename, and it can understand symbols that will label them in sequential order.
Unfortunately, you have to drag the new file name to each file; there is no way to highlight multiple files to rename them all at once. For numbered groups of files, however, Name-Dropper is faster than renaming and numbering each yourself in Windows Explorer.
When you launch Name-Dropper, a small, simple window opens. Drag the files you'd like to rename into the window. You can switch to a different view (List, Details, Small Icon, etc.) from a pull-down menu in the upper-right corner, and you can also reorder the files in the Name-Dropper window by dragging them.
Once you have your files in the Name-Dropper window, open Word or another an app from which you can drag text (you do so from the URL bar of a browser or the Google search field, should you so choose). At the top of the Name-Dropper window is a field labeled Drop Renaming Pattern. Here, you can type in text to rename your files, and you can also use placeholders <0> and <#> to order and number your files' names.
In my example above, I have a large batch of vacation photos with ugly names such as DSC_4487.JPG to which I'd like to give more descriptive names. I entered "Maine 2007 <0> <#>" in the top field of the Name-Dropper window. The <0> acts as a placeholder for the text I will drag into the window, and the <#> creates a sequential number order for my files.
From Word I started dragging the word "pic" into Name-Dropper, dropping it on each file, which was renamed Maine 2007 pic1.JPG, Maine 2007 pic2.JPG, and so on. All I had to do was drag and drop the word "pic" to change the names. It would be faster to make a batch change to all the files with one click, but Name-Dropper is still easier for renaming multiple files than going through Windows Explorer, right-clicking on each file, choosing Rename, and typing in a new name.
For a better app for renaming a large group of files, check out FreeCommander.