Le Sélect is one of the famous cafés in Montparnasse. Personally, I do go there for a coffee, a glass of wine before dinner or a simple snack like an omelette or a sandwich after a movie or a play, but not necessarily for any other food. However, the place is good for people watching and stays open very late, as is most of Montparnasse. For food, I do prefer the next door La Rotonde which is also slightly cheaper.
As far as I know, no website. For contact and hours see:
If you google 'Le-Select+Montparnasse' you come up with tons of info.