You can find a lot of logs in the /var/log dir, check it out.
You can restart a service after booting bij typing:
If you boot into the commandline and not into the graphical user interface you can use shift + pgup to scroll through the buffer.
If you do startup in a gui, you can examine the logs or reboot and put a 1 after the label. Using lilo this would be:
boot: linux 1
You will then boot in single user mode, log in as root and type: init 3 Linux will no boot to full multi user mode with networking, but without gui. User shift + pgup to check the output. The next time you boot everything will be normal.
I hope this will help you.