If you are planning on including Photo Galleries, these are the various settings you may want to alter.

Settings
Thumb size:
Set the width and height of the thumbnail images. If original ratio is set, only width will be applied.

Photo size:
Set height and width of the image which will be displayed in the Photo Album.

Maximum photo size:
Setting for maximum size (Width x Height) allowed for images to be uploaded. Images larger than this will not upload.

Maximum file size :
Set the maximum size [width] of uploaded images in bytes. Default is set at 150000 which is approximately 1.14Mb.

Thumb compression method:
This is dependent on host server settings. Default is GD2, if this doesn't work select GD1. Otherwise contact your host.

Thumbs per row:
Set the number of photo thumbs to display in each row in your album(s).

Thumbs per page:
Set the number of photo thumbnail images to display per page in your album(s).


Watermarks
Enable photos watermark:
If enabled, this will add a watermark image to your photos.
You will need to make one to suit your needs.
N.B. This setting is retroactive and will add watermarks to previously loaded photos.

Specify PNG watermark: Set the path to your watermark image, it must be .png format.

Save generated watermark? If watermarking is enabled, each time a photo is visited the server has to create the combined image.
This could greatly increase the server load on a busy site.
To prevent this, you can set this setting to yes which will save the image once and not have to be created each time the photo is viewed.
This will however, take up more disc space on your web server.

Enable text description on photos:
This will add album and photo name to your photos.

Album title colour, description colour and photo title colour:
Set the colours you want for the photo text descriptions.
Depending on your photos, this may take some trial and error to get it to display effectively on the images.