Firstly, check if the dependent software packages are installed:

INSTALL JAVA
# wget http://www.java.net/download/jdk6/6u21/promoted/b04/binaries/jdk-6u21-ea-bin-b04-linux-amd64-05_may_2010-rpm.bin

# chmod 755 jdk-6u21-ea-bin-b04-linux-amd64-05_may_2010-rpm.bin

# ./jdk-6u21-ea-bin-b04-linux-amd64-05_may_2010-rpm.bin

INSTALL ANT
# wget http://archive.apache.org/dist/ant/binaries/apache-ant-X.X.X-bin.tar.gz
# tar zxvf apache-ant-x.x.x-bin.tar.gz
# mv apache-ant-x.x.x /usr/local/ant
# export ANT_HOME=/usr/local/ant
# ln -s /usr/local/ant/bin/ant /usr/local/bin/ant

INSTALL SUBVERSION

# yum install subversion

BUILD AND INSTALL RED5

# svn co http://red5.googlecode.com/svn/java/server/tags/0_X _X/ red5
# cd red5
# /usr/local/bin/ant prepare
# /usr/local/bin/ant dist
# cd ..
# mv red5 /opt/red5

START RED5

# cd /opt/red5/dist
# ./red5.sh > start.log &

CONFIGURE RED5

# echo /opt/red5/dist/red5.sh > restart.log & >> /etc/rc.d/rc.local

When Red5 is running you should be able to access http://hostname:5080/ .
If it works first thing go to http://hostname:5080/installer/ and install admin.
Then to http://hostname:5080/admin/register.html and register an username and password.
Then you can check application statistics anytime from http://hostname:5080/admin/ with server ip/hostname and the registered username, password.
For newer version of RED5 (0.9 and higher), you have to follow these steps to enable admin

# cd /opt/red5/dist/
# mkdir plugins
# wget http://red5.googlecode.com/files/AdminPlugin-1.0.zip
# unzip -d /opt/red5/dist/plugins AdminPlugin-1.0.zip
# cd /opt/red5/dist/webapps
# mkdir admin
# cd admin
# wget http://red5.googlecode.com/files/admin.jsp

Restart Red5

# sh /opt/red5/dist/red5-shutdown.sh
# sh /opt/red5/dist/red5.sh &

 http://hostname:5080/admin/admin.jsp
Username: admin
password: the password for admin
New Password: not required as we are creating a new user here.
then access http://hostname:5080/demos/adminPanel.html
Server Address: hostname
and admin and password with which you registered.