Probably the easiest way, though officially depricated, you can "wrap" text around an image is by using the "align" attribute of the img tag. For example:
will cause the image to be displayed on the left, with text wrapping around the right side of the image.
This is an over simplification, because there are other parameters you can use to control spacing around images, etc, but this should get you started.
A better solution is to use a css style.
A quick "google" revealed this post on a WordPress support forum which (read the whole thread!) gives some good advice and show both ways to do it.