I've been using Linux (Mandrake 9.1, specifically) for a few weeks now, and I've got most of what I need working, but I have a couple of problems whenever I reboot.

Network: I set up my network connection using the Mandrake Control Center, and it works just fine. But then when I reboot there's no connectivity, and I have to do it again. It always works when I do it again, but is there a way to keep it set up?

CDROM: This is another one. I can type mount /mnt/cdrom at the command line, and it works just fine. But after a reboot I have to do that again. Is there a way to make this happen automatically?

You will need to give us an idea why the network isn't working. Can you post the output of:
ifconfig
route -n

Just after the reboot and after you have reconfigureed it.

As for the cd rom you could get it to mount automatically at boot but you will need to unmount it and mount it again when you change CDs.

Network:
What type of internet connection do you have ? (DSL, Cable modem, etc)

Make sure your network is active at boot-up.
Open a console and login as root (by typing su - )
Type the following command and make sure that 3 and 5 are on.
CD-ROM:
If you want to set up an automounting feature, you will need to edit the /etc/fstab file.
By default, Mandrake 9.1 uses supermount to mount and un-mount devices (CD-ROM, floppy, etc).
In your /etc/fstab, you should have a line that looks like this:
Take a look at this link for more information.
http://homepage.ntlworld.com/alex.ba...ke-faq.html#4e

This should work.

none /mnt/cdrom supermount dev=/dev/scd0,fs=auto,ro,--,iocharset=iso8859-1,codepage=850,umask=0 0 0

Works for mine at least.