That's basically it, but if I were you I'd download the combo update 10.5.6 from Apple support and use that as it's usually a more robust way of performing a system update. Once you've installed it you'll probably need to restart and then mount your type11 iso, run the installer.dmg and run the miniscript, selecting it to do an update as opposed to a new install.
After that you should be done. Good luck.
Dell Mini 9 2GB 64GB RunCore SSD BT 1.3MP 10.5.8 A05 NBI .8.3 RC3
MBP 2.4 C2D 4GB 160GB 10.6.2
Macmin 2.53 C2D 4GB 320GB 10.6.2
Macmini 1.83 CD 1GB 80GB 10.6.2
iPhone 3Gs 32GB; 2*PS3 (320/40GB + PlayTV); Wii; PS2; PSP Phat; PSP3000