It is a long-standing web design standard that the logo in the header area links to the homepage of the site. Another standard is that when displaying the navigation of a site, to highlight in some way the "current" page, if it is present in the navigation. I think those are great standards. The logo-link thing is so ubiquitous that your users will likely automatically try it if you've coded it that way or not. The current navigation thing is just good ol' horse-sense for grounding a users and making them feel good about their current location in a websites hierarchy.
But here is another good design standard: don't have links to the same page you are on, on that page.
The idea here is twofold:
- When you see a link, it looks like a link, it behaves like a link, that says "click this and be taken elsewhere." If the link takes you back to the same page you are on, that's kinda weird.
- It is a waste of server resources to reload a page for no reason.
How can you accomplish this without a bunch of development work and changing markup? CSS of course!