Near the end of last year Google finally opened up the full slate of Google services to Google Apps for your domain users. If you had previously set up dedicated accounts for dealing with AdWords or Google Analytics (as many business users have), you may want to transfer those accounts to your domain account. While Google doesn't explicitly discuss how to transfer such accounts, it's actually not too tough to do.
The basic idea in both cases is to add your Google Apps account as an admin user. You can then log in with your Apps account and remove the original account (if you so desire), effectively transferring ownership of the account to your Apps one. We've previously talked about some ways to get around multiple login problems by using multiple Chrome profiles or application shortcuts, but it's definitely easier to consolidate everything under one roof. You can get most of the benefit of this approach without ever deleting the original account as well, to ensure that all of your accounts have access to these services.
The procedure I outlined above is pretty straightforward, but I figured it was worth detailing it out to simplify the process a little further. Start by logging in to your AdWords account with your existing Google account (not you Apps account). Click on the "My account" tab, and choose "Account access." From there, add the email address of your Apps account as an admin user. There'll be a couple rounds of email verification to get everything squared away at which point, both your old Google account and your Apps account will both have full access.
Once you've granted access to your Apps account, and verified that the new access is working (I'd probably give it a day or two to make sure), you can log in with your Apps credentials and revoke access to the old account. Personally, unless you're dropping the old Google account entirely, I'd probably leave access to both accounts, but you can obviously that for your case.
The one snag I ran across when transferring our AdWords account was that I had inadvertently set up an AdWords account on my Apps account already. Even though I had never started a Campaign or run a single ad, it still wouldn't let me associate the existing account with my Apps credentials. To get around this problem, in the case of an empty account, you can just delete the account from the "preferences" option of the "My account" tab.
The procedure for transferring an Analytics account is basically identical. Unlike AdWords, a single user can access multiple GA accounts, so you shouldn't have any trouble adding in your Apps account, even if it is already linked to existing analytics. Start by logging in to your regular Google Analytics account, then click the "User Manager" link at the bottom of the page. From here, you'll add you Apps address as an admin user, and proceed as mentioned above.
As I said, there's nothing particularly complicated about transferring accounts in this way, but for whatever reason, Google doesn't explicitly mention it in any of their help documentation. In both cases, I definitely recommend exercising caution before deleting any old accounts. At the very least, sharing access across all your Google accounts can help avoid the multiple login problem that persists throughout Google's products.