There are a few ways to do this, but the most common is to use the <img> tag. This tag allows you to specify the location of the image file using the "src" attribute. For example, if you have an image file named "mypicture.jpg" in the same directory as your HTML file, you would use the following code to place it in your document:
<img src="mypicture.jpg">
You can also use the "height" and "width" attributes to specify the size of the image. For example, if you want the image to be 200 pixels wide and 300 pixels tall, you would use the following code:
<img src="mypicture.jpg" width="200" height="300">
If you want to place the image in a specific location on the page, you can use the "align" attribute. For example, if you want the image to be aligned to the right side of the page, you would use the following code:
<img src="mypicture.jpg" align="right">
There are other ways to control the placement of images on a web page, but this is the most basic. For more information, you can consult a good HTML tutorial or reference.