Can anybody advise me on how to paint a pine chest of drawers and bed which has a varnish on it please. I would also like to know if I can paint over wallpaper which is gold and slightly patterned with a coco colour - Many thanks

You need to clean the varnish by washing with mineral spirits and 0000 steel wool. Wipe with lint free towel and prime with a good sealing primer, possibley Kilz primer. Lightly sand the primed surface with very fine sand paper (220) and wipe with a tack cloth. Ready for paint.
The wallpaper is a different story. Painting wall paper with a metallic surface has never produced great results for me. Before painting wall paper have you tested a corner to see how hard it would be to remove it? Once you paint wall paper you have made it much more difficult to remove in the future.