When you have finished adding in-text citations to your document, place the cursor where you want your reference list and click Add/Edit Bibliography.
You can change the style of your in-text citations and bibliography by clicking Document Preferences. There are already a number of citation styles to choose from in Zotero, but many more can be downloaded from the Zotero Style Repository. Click on the name of the style to install it.
When you have finished your document, you can remove the connection to Zotero by clicking on Unlink Citations.