OWL-S Introduction

Hi, All, 

Could you let me know if you know the (pointers to) the introductory 
documents on OWL-S? Information on differences/relations with 
other technologies such as WSMO, WfMC, etc. are especially important. 

I need to prepare documents to explain OWL-S for lay IT people
(those not much into semantics/ontologies) in the company.

Thank you for your help,

Ryu