The websites have referee appointments listed on them except the SWPL, SWWC and SWWL.
You can use a link on the right to access a league. When you have finished on that league, simply click on the small white cross with a red background on the top right of the page and you will be back on this page.
This should make it easy to navigate between leagues.
A guide to using the league websites is available on the right.
There is a download available on the right but please be aware that the websites will be more up to date than the download.