On a pedestrian wayfinding scenario, I need to drape some extruded buildings close to the road as the user navigates along the road on a 2D Map Background. I hope I can use OpenLayers and ReadyMap for this. I have vector data in shape file format. I am a newbie to web-mapping. Any ideas on this to start with?
There isn't a huge amount of info to start helping you here. We need specific problems rather that general ones. Why don't you start with the OpenLayers Examples and take it from there. When you have a more specific problem then that is the point to start asking questions.
The OpenLayers Examples page is a really good starting point to see various things you can do with it and how, although bear in mind that some of them don't work all the time!