Locations of Important Files and Directories

MAKE.CONF : /etc/portage/make.conf
PACKAGE USE FLAG FILE : /etc/portage/package.use
PORTAGE LOGS : /var/log/portage
PORTAGE TMP FILES : /var/tmp/portage
LOCALE SETTINGS FILE: /etc/env.d/02locale Details UTF-8 Guide
GAYMES: /usr/games/bin (add user to the games group to access the gaymes)
LOCALE.GEN : /etc/locale.gen
KEYMAPS : /etc/conf.d/keymaps
XORG CONFIG FILE : /etc/X11/xorg.conf
.xinitrc (x startup script) : ~ home folder
.bashrc : ~ home folder

Using Gentoo with Virtualbox

Shared Folders
mount shared folders with mount -t vboxsf <sharedfoldername> <mountpoint>

Apply Locale Settings

After editing /etc/env.d/02locale (Details) do:

env-update && source /etc/profile

Portage

emerge --depclean will remove any packages that are not in the world file, and are not needed by any other package. Run it with --pretend first, to verify what is going to be removed
clean -d distfiles will clean up your distfiles directory. See the man pages of those tools.
emerge --searchdesc <searchterm> will search description of packages
emerge --search <searchterm> will search package names
emerge --sync or emerge-webrsync will update portage tree
emerge --update --deep --with-bdeps=y --newuse world performs full update

Updating Config Files

(see man emerge CONFIGURATION FILES section for details)
do find /etc -iname '._cfg????_*' and edit the files found manually

or do

etc-update

Wine

Wine directory: ~/.wine
Commands:
wine - execute windows program
winecfg - configure wine
wineconsole cmd - open a windows console

If the following error occurs:
err:wineconsole:WCUSER_SetFont wrong font
err:wineconsole:WINECON_Fatal Couldn't find a decent font, aborting
 Use export LANG=en_EN.UTF-8

Copy fonts from a Windows installation to the ~/.wine/drive_c/windows/Fonts/ folder for better font support

Other Useful Stuff

Mount/Unmount CD-ROM

mkdir /mnt/cdrom - make a directory
mount /dev/cdrom /mnt/cdrom - mount it to directory
umount /mnt/cdrom - unmount

Change Ownership of File

sudo chown <username> <file>

Disable Su

edit /etc/pam.d/su

su:

auth sufficient pam_rootok.so
auth required pam_deny.so <---add this line

Add User to a Group

usermod -a -G <groupname> <non-root username>

Uninstalling something you compiled manually

(use as root)
make uninstall
make clean

Extracting with Tar

tar : tar -xvf foo.tar
tar.gz : tar -vxzf foo.tar.gz
tar.bz2 : tar -vxjf foo.tar.bz2

Environment Variables

printenv - print all evironment variables
export VARNAME=value - set a new value

Scroll Up/Down in Terminal

Up - Shift + PageUp
Down - Shift + PageDown

Helpful Links