Best way to check patches on Metalink

http://metalink.oracle.com
Using Patches -> simple search with following details

Product and Family : E-Business Suite
Release : Applications R12
Patch Type : Any
Classification : Recommended
Plateform or Language : Select Relevant
Click on Go button. This search will show recommended patches.

OR

Click on Top right hand Side “Patches” , select “Quick Links to: Latest Patchsets, Mini Packs and Maintenance Packs” & you will see “Latest Oracle Applications R12 Packs”

Example : Let’s locate 10.2.0.4 patch for 10.2.0.1 baseline environment