Place your cursor in your Word file exactly where you want the citation to appear. Click the Insert Citation button on the EndNote toolbar in Word and enter a keyword to locate your citation, then click Insert.
EndNote toolbar (appears in Word)
You can also just select references in your library and turn them directly into a bibliography.
Select the references you want to include in your bibliography, then click References menu / Show Selected References. Click File menu / Export… then choose a file name. Save as type Rich Text to create a Word- or WordPerfect-compatible file, or HTML to create a web bibliography.
If you're using a style that calls for page numbers in citations:
Select the citation in your text by clicking on it.
Click the "Edit Citations" button in the EndNote toolbar.
A window like this one will appear. Just enter your page numbers in the Pages box and click OK. EndNote will add them to your in-text citation or footnote.
In the Edit Citations window you can also control other aspects of the citation's appearance. Exclude the author or year if you have already mentioned it in the text, or add a prefix or suffix (like "see also").
There's one extra step if you're inserting a reference into a footnote.
Click the References tab in Word. Click the Insert Footnote button.
With your cursor still in the footnote, click the EndNote tab in Word and then the Insert Citation button as usual. (Wherever your cursor is in your document -- the body or the footnote -- is where the citation will appear in the document.)