The three items which you mentioned are key items to get your desktop loaded faster.
To edit the daemons / process that start at boot time, open Menu> System> Services. Unlock the window with your user password. If you don't use,
1. Printing devices, turn off CUPS. (this one usually takes a lot of time for loading).
2. Bluetooth enabled devices, turn off Bluetooth.
3. WiFi enabled devices, turn off any WiFi services.
Now, in Menu> Settings> Autostarted Applications, if you don't use
1. Printing devices, turn off Print Queue Applet
2. WiFi enabled devices, turn off Wicd.
Alternatively, you can remove CUPS, Bluetooth and WIcd related S/W from you system through Synaptic package manager. But, mind the dependencies, please; i.e. don't remove any S/W on which your other required S/W is also dependent. There are many printer drivers from HP and others, and all the three S/W categories mentioned, put together take more than 100MB of harddisk space. If you would like to experiment or are pressed for harddisk space, go ahead and remove them. If you have enough harddisk space, you can refrain from taking the pains of hunting for these programs in the package manager and relax.