installing R on Ubuntu

I've read some of R's literature on Linux, including the R Admin manual, and
didn't find it very useful, which is probably my own limitation.  But I did
finally manage to get it working well.  I'm posting this to help others. 
The following worked when installing R 2.8.1 on Ubuntu 8.04 Hardy Heron. 
Here are truly step-by-step instructions for those who don't know Linux
(like me):

Installation and Initial Set-Up of R for Ubuntu Linux

1. Open the Bash terminal (Applications > Accessories > Terminal)
2. Type these lines to add the security key to access the latest version of
the R Ubuntu package:
	user at computer:~$ gpg --keyserver subkeys.pgp.net --recv-key E2A11821
	user at computer:~$ gpg -a --export E2A11821 | sudo apt-key add -
3. Use the Bash terminal to open your sources.list file with gedit (text
editor) for editing:
	user at computer:~$ sudo gedit /etc/apt/sources.list
4. Add this line to the bottom of the sources.list file:
	deb http://rh-mirror.linux.iastate.edu/CRAN/bin/linux/ubuntu hardy/
5. Save the file and go back to the Bash terminal.
6. Type this to update apt-get's database before you install R:
	user at computer:~$ sudo apt-get update
7. Install R with this command:
	user at computer:~$ sudo apt-get install r-base
8. Go to System > Administration > Synaptic Package Manager, and download
the build-essential package.
9. To use R, simply enter R in the Bash terminal.  To quit, enter q().


Additional programs will be needed to install other packages or work with
other programs:
1. Install compilers for C++ and Fortran
	user at computer:~$ sudo apt-get install g++ gfortran
2. Install the developer versions of Blas and Lapack (what are these?)
	user at computer:~$ apt-get install libblas-dev liblapack-dev


Updating Packages in R
1. Open the Bash terminal and start R with root permissions
	user at computer:~$ sudo R
2. Type > update.packages()


Installing the R Commander GUI
1. Open the Bash terminal and type:
       user at computer:~$ apt-get install r-cran-rcmdr 


Using the R Commander GUI
library(Rcmdr)
...or once the library is open and Commander has been shut down, type:
commander()


Notes
It looks like most of R has been put here:
/etc/R (Rprofile.site is here)
/usr/lib/R


Downloaded Packages seem to go here:
/usr/local/lib/R/site-library/