Look at the RHS books - most have photos, and I couldn't do without mine. I have the RHS A-Z Encyclopaedia of plants. It is expensive, but worth every penny. It has a list of common names as well as the botanical ones. Look at Amazon for good prices!

so have I -- its a wonderful book --

Me too - I refer to it as my bible

ageed Andrew :)

And me! LOL.

ditto :o)

We have two of them... the old one, with pages that are making the great escape, in our potting/work shed so we can check instantly and the new 'posh' two volume one in the house. It is very much a bible for us.

It is usually my first point of reference for any plant. It is often available in second hand book shops and the information does not change that much.
"A-Z Encyclopedia of Garden Plants" publish by DK.

I recommend the "Flora" A-Z by Cassell, which also has fantastic pictures.
It's about the same size as the RHS A-Z, but has different things in it.
I bought it after buying plants and then getting frustrated because the RHS book didn't list them.

RHS Encyclopaedia gets my vote, though I prefer the Reader's Digest Encyclopaedia for other reasons - I use the two together, but only the RHS one has a list of common names in the back.