Creating an image gallery in WordPress is quite easy. Here is the step-by-step method.

Click on the “Create Gallery” link on the left menu.

This will bring you to the image selection dialogue box.
To select the images for your gallery, simply click the image.  You will see a check mark on the top right of the images you’ve selected, as well as seeing the image thumbnails at the bottom of the dialogue box.

Once you have your images selected, click the “Create a New Gallery” button on the bottom right.

In the next dialogue box, you can edit the images within the newly created gallery.

Here you can reorder the images by dragging and dropping, or you can reverse the images by hitting the “Reverse Order” button.
On the right menu, you can choose what each image links to in the “Link To:” drop down box.   You can also set how many columns you’d like in the gallery and you can choose to have the images in random order.
Once you are happy with your selection, hit the “Insert Gallery” button on the bottom right.
My gallery is below.

creating an image gallery