As part of my induction for JIRA support i've gone through the 4.4 installer guide and here's some feedback I've got. I've formatted so that the link to the page is followed by the issue I'm discussing.

http://confluence.atlassian.com/display/JIRA/Installing+Java

• linux commands for setting JAVA_HOME missing (though this could be because of differences in distro) But I found that this is pretty standard...
  echo JAVA_HOME="</PATH/TO/JAVA>" >> /etc/environment

http://confluence.atlassian.com/display/JIRA/Installing+JIRA+Standalone+from+an+Archive+File+on+Windows%2C+Linux+or+Solaris

Can we make a note and link that using the .bin file is recommended over doing it manually from the archive file

1. Download and Extract the JIRA Standalone Archive File

This did not suggest where to put JIRA in the first place, though I understand if this is purposeful... we could say something like this if we thought it necessary.
mkdir -p /opt/atlassian/jira
mv *.tar.gz /opt/atlassian/jira
cd /opt/atlassian/jira
tar xfvz atlassian-jira-4.4-*.tar.gz
ln -s atlassian-jira-4.4-BLAH current

2. Set the JIRA Home Directory in JIRA

Can we have the path of application.properties without having to click for it?
./atlassian-jira/WEB-INF/classes/jira-application.properties

Only a small thing but I think it's more of a convention to use </suggested/paths> as such.
export JIRA_HOME = </path/to/jira/home>
Can we give an example that it's usually set as something like /var/atlassian/jira ?

I think exporting can be risky because the system will forget it when logged out and in again. Instead maybe something like:
echo JIRA_HOME=/var/atlassian/jira >> /etc/environment

3. Create a Dedicated User Account on the Operating System to Run JIRA

Can we suggest a dedicated user account AND group?

groupadd atlassian
Then add the user jira and put it into the group atlassian:
useradd --create-home --comment "Account for running JIRA" --shell /bin/bash jira -G atlassian

Suggestion for setting permissions
chown -R jira:atlassian </path/to/jira/install>
chmod 770 </path/to/jira/install> (please tighten for security if necessary)
chown -R jira:atlassian </path/to/jira/home>
chmod 770 </path/to/jira/home> (please tighten for security if necessary)

4. Start JIRA

Wait until the following message appears in the application's log file: - give path to log file instead of having to click elsewhere.

If JIRA does not appear in your web browser, you may need to change the port that JIRA runs on.
Also suggest to check OS and network firewalls

http://confluence.atlassian.com/display/JIRA/Running+the+Setup+Wizard

Can we please link to a page on dragons (or wherever) that tells the customer how to set up on different databases eg: postgres...

Basic Postgres setup information:
yum install postgresql84-libs.x86_64 postgresql84-server.x86_64 postgresql84-devel.x86_64
su postgres
initdb /var/lib/pgsql/data

• check postgresql.conf
  (adjust security)
  listen_addresses = '*'
• check pg_hba.conf
  (adjust security)
  host all all 0.0.0.0/0 trust
  exit
  /etc/init.d/postgresql start
  su postgres
  createuser jira_user
  Shall the new role be a superuser? (y/n) n
  Shall the new role be allowed to create databases? (y/n) y
  Shall the new role be allowed to create more new roles? (y/n) n
  CREATE ROLE
  $ /usr/local/pgsql/bin/createdb jira_db -O jira_user
  CREATE DATABASE
  test database and enable password:
  psql postgres postgres
  \l (lists all databases)
  ALTER USER postgres WITH PASSWORD 'tmppassword';

http://confluence.atlassian.com/display/JIRA/Connecting+JIRA+to+PostgreSQL#ConnectingJIRAtoPostgreSQL-databaseconfig

Open a console and execute config.sh in the bin subdirectory of the JIRA Installation Directory.
Can we make a note that the costumer will need a GUI on Linux for this.

http://confluence.atlassian.com/display/JIRA/Installing+JIRA+Standalone+on+Linux

I thought that the name was a little generic "Installing JIRA Standalone on Linux"
Maybe can we change it to something like "Installing JIRA Standalone on Linux using self extracting setup wizard"?
Reiterate that this will be the recommended way to perform an install

If JIRA does not appear, you may need to change the port that JIRA runs on.
pelase add "Also check OS and network firewalls blocking your chosen port"