Minimal user role: contributor

• To find a page you recently did you can go to 'Recent posts', which is a menu item under your user name on the left side.
• To find all of your pages go to 'My account', which is also a menu item under your user name. Click on 'Track' and you will get a list of your pages. 
• To find all nodes of a certain content type click on the link to this content type (e.g. 'Page' or 'Image') in the 'Content' menu on the left side. You will get a list of all the nodes of this type.
• Click on the title of the page you want to change and click on 'Edit' (in the row below the title). Now you can change or add to the data you already entered, and then submit.

It might be confusing to know what to do when you work with the panels on the species pages. You have to click on the title of the item in the panel to go to the respective page and only then you can edit it.

To edit pages other users created you need to have the role of editor or you can ask the respective creator to give you access to this page.