Here is a great article on how to install the iSCSI software initiator on Linux and then connect to volumes.
http://www.cyberciti.biz/tips/rhel-centos-fedora-linux-iscsi-howto.html

The article mentions the steps were tested on Redhat Enterprise (RHEL) v5, CentOS v5, Fedora v7 and Debian/Ubuntu Linux.
I went through the steps on a CentOS v5.3 x64 machine and it worked flawlessly.

Here’s another link when working with the Linux Device-mapper Multi-pathing with iSCSI:
http://www.cyberciti.biz/tips/rhel-linux4-setup-device-mapper-multipathing-devicemapper.html

Here is a link on working with SAN Snapshots and mounting that snapshot volume to a Linux host:
http://knowledgelayer.softlayer.com/questions/405/How+to+connect+to+an+iSCSI+Snapshot

Here are also some useful Linux and iSCSI documents from HP Lefthand that we’ve uploaded to this blog:
Setting Up iSCSI volumes on CENTOS 5, RedHat 5, Fedora 7 and, Debian
Configuring CHAP authentication with the linux iscsi initiator
LeftHand Volumes with SUSE Linux iSCSI