GeoServer is an open source software server written in Java that allows users to share and edit geospatial data. Designed for interoperability, it publishes data from any major spatial data source using open standards. For more info visit Geo Server Web page. I installed Geo Server and ( find how to install ) it is working very well, but in this post blog I would like to tell you have to use OpenStreetMap data in GeoServer. You can download directly shape files from CloudeMade, but you can use and Quantum GIS for converting OSM files in shape files after that to use in Geo Server.
How to convert OSM files in shape files with Quantum GIS
You need to open Quantum GIS and you need to install OSM plugin for Qauntum GIS, after that you need to open OSM files in Quantum GIS. Right click in the files of OSM and after that you need to click at Save as like in picture, after that you need to save with ESRI shape file format like 3 steps in picture.
Than easly you can upload the shapefiles in GeoServer.