bullet points in text widget

Use HTML code:

<ul>
<li>Point 1</li>
<li>Point 2</li>
<li>Point 3</li>
<li>Point 4</li>
</ul>

Replace <ul> and </ul> with <ol> and </ol> for a numbered list.

More info – http://www.w3schools.com/html/html_lists.asp

Place it in a text widget – WP-Admin > Appearance > Widgets

http://codex.ww.wp.xz.cn/WordPress_Widgets#Using_Text_Widgets