We are looking at using LLBL with our web application, but the only book I see available appears to focus on winforms. Is there any references for Web Development ? Any differences that are needed to run Win vs. Web?

Check the port of MS Petshop at http://www.llblgen.com/pages/secure/filestreamer.aspx?filename=Example_Petshop_10242005.zip

This will give you an idea how to use the low level business layer in ASP.net applications.

LLBLGen Pro generates a Data Access Layer with Business Objects (Entities). Generally there is no difference using them in a Windows app. or a Web app.