The following is a list of tutorials you may find useful.

RPG Tutorial

This tutorial walks you through everything from setting up HaxeFlixel, to making a working, top-down, turn-based RPG.

Project Jumper

This tutorial, by Chipacabra, shows you how to make a platformer game.

Note: this tutorial was written in AS3 Flixel, and ported to HaxeFlixel. Your mileage may vary.

Haxecoder

Haxecoder has a couple of HaxeFlixel tutorials, including one to help you get started, and another RPG.