The dials you see there are, from left to right, for paper-grade and for neutral density (used to give enough time for dodging when making smaller prints).
A timer will sit between the mains cable from the enlarger and the mains socket in the wall. I'd suggest looking for one which has dials to set tenths, units and tens of seconds. This will enable you to more easily work in fractions of a stop with your exposures. Note that any timer brand will do the job - perhaps one from Philips is the most common in Europe, having the functionality I describe.