Apple's Pages word processor for OS X is great for document creation, and is an excellent alternative to Microsoft Word for many needs; however, because Word is the de facto standard for word processors you may often find yourself needing to send someone a document or two in a compatible format.
While you can choose "Print to PDF" or another option from the PDF menu in the print dialog box in OS X to quickly create a static version of the document to send to someone as a PDF, this isn't the best approach if you need the recipient to be able to edit the document.
An alternative is to use the Export option in Pages to save the document in the Microsoft Word format, which can be edited by other people. To do this, simply go to the File > Export menu where you will see an option for Word and some more generic formats like RTF and TXT.
While this is simple enough, if you find yourself exporting to Word frequently then you may want to set up a custom hot-key combination to activate this feature. To do this, go to the Keyboard system preferences and in the Keyboard Shortcuts section select "Application Shortcuts," then click the plus sign to add a new shortcut. Choose Pages from the drop-down menu (or choose Other and manually add it to the menu if it's missing) followed by typing "Word..." as the command (the three dots are separate periods and not an ellipsis). Next assign a hot-key combination of your choosing, making sure that it does not conflict with any other Pages hot-key commands.
Since this export option brings up a dialog box with options for the other supported formats as well, you do not need to necessarily create custom hot keys for them. However, if you use one of the other formats more often, you can assign your hot-key combination to one of them instead of Word, and that format will become the one selected as default in the export dialog box.
A final way to export a Pages document to Word is to have the program create a copy of the document as a Word document when you save. To do this, select Save from the File menu for your new Pages document, and when you select the location to save in, check the option to save a copy as a Word document.