To customize the dashboard icons that you have in your members area, go to Design Layout > Site Layout and click on the View Dashboard Icons button.
You can enable or disable icons that you want, as well as add new ones. Click on the Add Icon button to add a new icon to your member dashboard.
Keep in mind that certain icons will only show up if the user has permission for it. For example, if he / she is an affiliate, he /she will be able to see the Affiliates, Commissions, and Traffic icons.
To rearrange the icons, just hover over one and click and drag it to position it wherever you want in the list of icons.