Deleting a page is a straightforward operation for anyone with sysop permissions. Users without such permissions can still remove text from wiki pages, or propose/request that a page should be deleted.
Before deleting you could perform various checks:
- Use the "What links here" tool. This gives an indication as to how important a page is, and what subjects it relates to. Perhaps the page is still linked to prominently from many places. All incoming links will become red links if you proceed with the delete. Ideally all incoming links should be changed/removed, if there is genuinely no need for this page to exist. You could do this work prior to deleting, or ask others in the wiki community to do it.
- Check the page history and the associated talk page. Who was proposing the deletion? Does anyone disagree? Has it been properly discussed? Did people have adequate time to raise objections? Did somebody vandalise a page, which then led to a deletion proposal?
The care taken over these things might depend on the size of the wiki community, and how clear-cut the case for deletion is. Remember that only sysop users can undo a delete action, so to a normal user the information appears to be lost forever.
Use the 'delete' tab
Sysops should see a 'delete' tab at the top of every page. Click this to delete the page. You will be asked to confirm, and to supply a "Reason for deletion". This is a short textual description of why the page is being deleted. Your action will appear on the recent changes display, and in the deletion log (Special:Log/delete).
To undelete a page you must navigate to the exact page name of the page. You can find this in the deletion log (Special:Log/delete) if you don't remember it.
You should then see a link to "View or restore n deleted edits". Tick the box next to the revision you wish to restore.