Just open "System Preferences", and click on "Accounts". Select your account, and click on the "Startup Items" tab.
Drag your networked volumes into the list. You can put them anywhere you like, e.g. first if you want them to mount early, before any of the applications launch.
You might want to save the passwords on your keychain before you do this, if you want everything to go smoothly. If you don't, you'll have enter your credentials for every one of the volumes in turn.
Just make sure noone can access your account without loggin in with name and password, i.e don't enable "Automatic login" if you value your privacy and the integrity of your data. But you knew that already.