I was original going to fit this type of bracket
http://www.screwfix.com/sfd/i/cat/42/p1384042_l.jpg

However the drawback on this type is the space below the shelve that
one has to leave.

Ideally I like the ones that are fitted to bookcases. ie 4 clips, 2 on
each side (similar to kitchen shelves).

But other than fixing a board either side, I can't figure out how best
to do this.

If I do fit a board either side, it will certainly make it look better
inside the cupboard. But I've never fitted bookcase version that can be
seen here
http://www.screwfix.com/sfd/i/cat/50/p1388750_l.jpg

Do I need to router out a groove for this type ? If so has anyone
reading this done this before ?