Coordinate Systems and Raster Data

Hi,

I am a complete beginner to GIS, so forgive me if this seems obvious.
I have raster data on environmental variables such as forest cover and urban extent, and vector data on species geographic ranges. The species range size data is in GCS_WGS_1984 format and the raster data are in GCS_Clarke_1866. How do I convert GCS_Clarke_1986 into GCS_WGS_1984?

Also I am trying to extract the raster data from the polygons of species range size, can I do this on the basic version of Arc10 (with nno extensions)?

Thanks