It’s been a common (and growing) convention for several years now that the site logo (typically in the top left corner) also acts as a link back to the site’s home page. But you’d be surprised how many people don’t know this. I always find one or two each time I do user evaluations.
Amazon’s recent redesign helped make this convention more findable, by “buttoning-up” the their logo on mouse over. (If you are reading this in email form, click into the blog to see the screenshot.)

Related to this comes to general guidelines:
On the home page itself, the logo shouldn’t be link, ‘cause it would be linking back to itself Always provide an alternative, more obvious link back to the home page, somewhere on the page, even if it’s in the footer.
It’s a great practice to spell out contact hours on a company website and expectations for when someone can contact you and how long the normal turnaround is for a response.
But timezones are often overlooked. Or if they are acknowledge, it’s just a qualifier (eg. 9am - 5pm AEST) and the person reading it has to do the work to translate it into their local time.
Iconfactory, makers of the Twitter client Twitterific, do a great job at being helpful with their contact times - showing the local time and if the office is currently open or closed.
REX’s online flight booking form is probably the worst I’ve used. At every turn it surprises with a new way to have a poor experience.
My favourite is this dialog that comes up to confirm you don’t want flight insurance. Mind you, you’ve already explicitly said you don’t, but they are just checking. And to continue with your booking and confirm that you don’t, you have to press Cancel. Yes, Cancel.