Ubuntu - Log files and Moving HDD to another box - wrapping head around differences with Windows Server

Currently in place - Ubuntu 8.04.1, as a Currently in place - Ubuntu 8.04.1, as a File Server (Samba)/Web/Mail/Users
Looking to upgrade to Ubuntu 10.4LTS
I have no Ubuntu experience, less installing it on a desktop.  
I have good knowledge of Microsoft
Looking to upgrade to Ubuntu 10.4LTS
I have no Ubuntu experience, less installing it on a desktop.  
I have good knowledge of Microsoft

Is there a central depository for error messages or are they stored in each programs directory?
i.e.
Something wrong at boot, where do you go for troubleshooting info.
and
Something wrong with individual module, File Server/Web/Mail, where do you go for troubleshooting info.

Also,
When moving a drive in Windows, you can change the HDD drivers in the registry so that you can move the drive to another box with different chipset.  How would this work in Ubuntu?