If you are using a laptop, you will want to be able to suspend (save your session to RAM and resume to it quickly), hibernate (save your session to the hard drive) and keep it cool by using cpufrequtils.

Suspend and Hibernate

First you will need to install pm-utils, the new framework for suspend and hibernate pacman -S pm-utils

Configuration

Next you will set up hibernate. First open /etc/mknitcpio.conf as root with your favourite text editor and add

HOOKS="... resume filesystems"

Make sure it is after ide, scsi and sata, and before filesystems. Now run mkinitcpio -p kernel26 Open your /boot/grub/menu.lst as root with your favourite text editor and go down to your Arch Linux part and add

# (0) Arch Linux
title Arch Linux
root (hd0,0)
kernel /boot/vmlinuz26 root=/dev/sda1 ro resume=/dev/[swap partition]
initrd /boot/kernel26.img

Where it says [swap partition] you will need to put something like "sda3". If you don't know what it's called, run fdisk -l and look for the one that says "Linux swap / Solaris". Look to the left and it should say what number it will need to be.

CPU Frequency Utilities

If you are using a laptop you will want it to stay as cool as possible. You can install CPU frequency utilities to scale your CPU to a lower frequency when it doesn't need to be so high, saving power and keeping it cool. First you will need to install it. Type pacman -S cpufrequtils

Configuration

Now you will need to set up which modules you need. For most users you will need the "acpi-cpufreq" module. If you are using a Pentium 4, you will need "p4-clockmod". Certain AMD processors will need either "powernow-k6" or "powernow-k7". If you want the module to start at boot, open your /etc/rc.conf as root and add the name of the module you need in the modules line like so:

MODULES=(acpi-cpufreq cpufreq_ondemand...)

To load the module now, run modprobe acpi-cpufreq To see information about your CPU, run cpufreq-info the output will look similar to analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which need to switch frequency at the same time: 0
  hardware limits: 1000 MHz - 1.50 GHz
  available frequency steps: 1.50 GHz, 1000 MHz
  available cpufreq governors: powersave, ondemand, performance
  current policy: frequency should be within 1000 MHz and 1.50 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 1000 MHz.
analyzing CPU 1:
  driver: acpi-cpufreq
  CPUs which need to switch frequency at the same time: 1
  hardware limits: 1000 MHz - 1.50 GHz
  available frequency steps: 1.50 GHz, 1000 MHz
  available cpufreq governors: powersave, ondemand, performance
  current policy: frequency should be within 1000 MHz and 1.50 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 1000 MHz. You can now use programs like KPowersave and Gnome Power Manager. If you are using a lightweight window manager and don't want to install excessive Gnome or KDE dependencies, you can run cpufrequtils through a daemon. First you will need to edit /etc/conf.d/cpufreq as root. It should look like this:

#configuration for cpufreq control
# valid governors:

# ondemand, performance, powersave,
# conservative, userspace governor="ondemand"

# valid suffixes: Hz, kHz (default), MHz, GHz, THz

min_freq="1GHz"
max_freq="1.5GHz"

Info
You can comment out "min_freq.." and "max_freq..." if you want to. Everything is automatic If you don't know what to put into it, run cpufreq-info and it should tell you the min and max frequencies. Now if you want to have the daemon start at boot, open your /etc/rc.conf and add

DAEMONS=(..cpufreq...)