Start here:
http://downloads.mercury.com/
it's very self explanatory.... you can download eval copies of TestDirector, QuickTest Professional, WinRunner, LoadRunner.
Here are the other products you can download with your free account.
Mercury Diagnostics Profiler
Mercury QuickTest Professional 8.2 for StingrayEvaluation
Mercury QuickTest Professional 8.2 for VisualAge Evaluation
Mercury QuickTest Professional 8.2 for Peoplesoft Evaluation
Mercury QuickTest Professional 6.5 Evaluation
Mercury QuickTest Professional 8.2 for Oracle Evaluation
Mercury QuickTest Professional 8.2 for Java Evaluation
Mercury QuickTest Professional 8.2 for Siebel Evaluation
Mercury QuickTest Professional 8.2 Terminal Emulator Add-in Evaluation
Mercury QuickTest Professional 8.2 for SAP Evaluation
Mercury QuickTest Professional 8.2 for .Net Evaluation
QuickTest Professional 6.5 Java Add-in
Introduction to Quality Center 8.0 - Using TestDirector: Computer-Based Training (CBT) Course
Oracle Solution Template
Introduction to QuickTest Professional 8.0 Computer-Based Training (CBT) Trial Version
Microsoft Active Directory Solution Template
Microsoft Exchange Server Solution Template
Introduction to SiteScope 7.9.5.0 Computer-Based Training (CBT) Trial Version
SiteScope WebLogic Template
SiteScope WebSphere Template
SiteScope Siebel Monitor
SiteScope WebSphere MQ Monitor
Mercury QuickTest Professional 6.5 for Siebel Solutions Evaluation
Mercury QuickTest Professional 6.5 for SAP Solutions Evaluation
Mercury QuickTest Professional 6.5 for PeopleSoft Enterprise Applications Evaluation
Mercury QuickTest Professional 6.5 for Oracle Evaluation
Introduction to Mercury LoadRunner Computer-Based Training (CBT) Course
Mercury QuickTest Professional 8.2 Evaluation
Mercury Managed Services Evaluation
Mercury SiteScope Evaluation
LoadRunner 8.0 Free 10-day Trial
Mercury SiteScope Upgrade
Hope this helps...