Hi! Some really useful features to look for in highchairs are:
*Height adjustable (adjust it to suit the height you are sitting at).
*Reclining seat (great when starting on solids and bubs isn't able to sit upright yet).
*Castor wheels (handy to move around easily).
*Ease of use when folding down to store away.
One of the most popular models which do all this is the Peg Perego Prima Pappa or the Chicco Mamma, but there are heaps of other immitations which are just as good and cost heaps less.

Make sure you choose a highchair you are 100% happy with because they do get a lot of use!

Good luck!