1. Install Lion
If you heard about the small business 20-pack of licences Apple offered when they announced Lion and think you might want to go that route - don't. Trust me. They can take your payment but they just can't fulfill your order ... and that's really the most important part. Two months later I have a micro USB drive and am finally starting the upgrades.
2. Use App Store to download & install XCode
Annoying. At least they fixed the download process to support resumes. Mine cutoff at 98% of the 4G download but picked back up where it left off on resume.
3. Run "/Applications/Install Xcode.app"
So when App Store said it was "Installing Xcode" it meant it was installing the Xcode installer. Sadly, it took me a while to figure this one out ... and I am not alone.
4. Install MacPorts 2.0.3 or greater
MacPorts install for Lion worked the first time with no hassle - Apple could learn a thing or two.
5. Run "port upgrade outdated"
This takes some time but ran without error for me...nice.
6. Update php.ini
Lion upgrades to PHP 2.3.0 and saves but disables your existing php.ini - at a minimum you'll need to update your mysql socket entries to point to the same place as your my.cnf
7. Install a JDK
I attempted to run a Java driven app (LibreOffice) and Lion magically prompted me to install Java. I let it and the install process flawlessly setup a full JDK instead of just a JRE - nice job Apple.
8. Toggle trackpad scroll direction
If all my devices used Lion I'm certain I'd adapt to the inverted scrolling in just a few hours - but they don't and that causes wheel spinning everytime I begin a Lion based session. I see no net benefit so it's not worth the pain. System Preferences -> Trackpad -> Scroll direction -> unchceck
9. Install the updated Server tools
If you run a Mac Server and want to use your Lion workstation to manage its services...you need the updated Mac Server Tools.
10. Disable Dashboard
I don't care for widgets.
defaults write com.apple.dashboard mcx-disabled -boolean YES
killall Dock
11. Install JDK source
Grab the Java for Mac OS X 10.7 Developer Package from http://connect.apple.com/
It'll put the src.jar here
/Library/Java/JavaVirtualMachines/1.6.0_26-b03-383.jdk/Contents/Home/src.jar