Searching through code is one of the more important features of an editor.
If you are familiar with search in Eclipse, Sublime is a bit different but has the same power.
CTRL+F is your basic in file search. Enter your text, click find (or hit ENTER or F3) and your search text will be found in the file.
CTRL+SHIFT+F will search across your project. What's nice is you have a lot of control over where you search ("in location") and which files you want to search for ("in files").
One thing that stumped me at first was the search results. These are opened in a new tab as a text file. Say what? Then I thought it was cumbersome to then have to open the file (CTRL+P) and search within it for the text. I realized however that you can click on the search results themselves!
You can click on the file name and it will open that file. Or if you click on the search text you were looking for, it will take you to that location, within the file it was found.
When searching also make note there are additional options like match case, whole word search and the ability to use regular expressions.
Update 12/6/2012 The search dialog has been tweaked, from the change log: "Find in Files panel now has a single "Where" field, combining the previous "In Files" and "In Location" fields"
Now you can enter something like: "Where: Z:\myproject,.cfm,.cfc"