Just to add something here. The terms 'Flyback' and 'forward' are normally reserved for transformer based designs. With a single inductor, this is just normally called a boost. A flyback stores the energy in the transformer, then dumps it into the secondary. An air gap enables the transformer to store more energy which is why a flyback needs an airgap. With a forward converter, put simply, you are imposing a square wave on the primary that is transformed to a square wave on the secondary. No (or very little) energy is actually stored in the transformer, so you dont need the airgap.
A boost converter is (technically) a flyback (it dumps its energy into the load when the FET switches off and the inductor voltage flies back), but dont use this term to refer to a boost converter as most people refer to flybacks as being transformer based
If you want to understand boost converters a bit more, please see my tutorial:
http://www.simonbramble.co.uk/dc_dc_converter_design/dc_dc_converter_design.htm
You can normally simulate most things like this in LTSpice. Here is my LTSpice tutorial:
http://www.simonbramble.co.uk/lt_spice/ltspice_lt_spice.htm
I hope this helps
Simon