Follow the steps which I have mentioned.If you want to start with BPEL you can do either of the two things.
1) If you are interested in only BPEL then download and install BPEL server from oracle site. For coding you need to have Jdeveloper.
2) If you want to use all the components of SOA then download version 10.1.3.1 and install SOA suite. Apply Patch to upgrade version to 10.1.3.3.
After installation of server, download Jdeveloper 10g and Unzip the file to use it.
I am currently working on Oracle SOA Suite 126.96.36.199. Having a Composite BPEL process , which is acting like router + transformation of messages according to the called sub process.
During compilation of process ( not sub-process) , its hanging.