I would start with an oil change. Then plugs, air filter and change the coolant. I'd probably change the brake fluid and check the pads etc as well.
I find it best to do everything in one go. By the time you take one bit off to get to another, you may as well do it all.
Valve clearances should have been check at 15000 miles. If all seems well they probably have.
Also when doing a service I like to clean everything and lube cables etc as I go.
Hope that helps!
When you've done all that you should be up to scratch. As far as intervals go, I tend to do bits as and when I feel they are needed. Keep the chain well lubed though.