Which bicycle (for a novice) would you recommend?

Get the Raleigh. It'll be fine on LIMITED dirt trails (ie less than 100 m at a time), and will be much easier to ride those distances on. The energy lost through a CX bike's semi-knobby tires on asphalt would make it much more of a chore, especially for a novice. On a real road bike, it'll fly by. If you find yourself yearning for trails, get a cheap used hardtail mountain bike. A decent one is easier to find than a cheap used road bike.

Oh man, fuck that bike store. Unless things are waaay more expensive in Australia, an entry-level road bike should not cost you that much. My recent search was for women's specific frame road bikes and ~$650 usd was the cheapest in most of the brands I looked at. My parents and boyfriend all have that they like. It's basically a road frame with flat handle bars for a more comfortable ride. They are cheaper than road or cx bikes. According to the http://www.trekbikes.com/au/en/bikes/bike_path/#fx website, they start at $400. I used to take my boyfriend's FX on group rides with mostly road bikes and while it was a bit more work (upright position=more wind resistance), I could still keep up with them.

Just want to say: a heartfelt and big thank you to everyone. I managed to pick up a used road bike in excellent condition, with a carbon frame, and full 105 gearset, for a decent price. I've learnt a hell of a lot this weekend - and I've got a sneaking suspicion that this is about to become an addiction of sorts. Very exciting!

The Raleigh Airlite 400 has a Shimano 105 drivetrain/components compared to a tiagra (or tiagra/sora) mix for the others. That is a definite step up in quality and it's the cheapest in price to boot.

I see from your previous question that you plan to ride on gravel trails, which is why people suggested a cyclecross bike. You don't want to ride a road bike on gravel for any distance, but it'll be just fine on a cyclecross with the right tires.

Is here any reason you're not considering a cheap, steel mountain bike beater?

As chrchr says, if you plan to use this on gravel, you want something sturdy and with considerably fatter tyres than 25s. A carbon fork probably isn't your best bet on the rough stuff either. It'll get chipped, and then it'll crack. Which is a pity, because the parts on the Raleigh are distinctly better than the other three. That said, the Tiagra gear on the Kona is only one step down from the Raleigh's 105 kit, and should see you fine. Go the Kona!

@Ahab & @chrchr The main attraction of the cyclecross was that it kept my options the widest open! I guess this is the point where I have to decide what my ambitions are - the vast vast majority of use will be on sealed roads and paths. I'm not really sure if I'll take up riding on dirt trails (and less likely, gravel) - just didn't want to close any doors. I figured a cyclecross would be the best compromise, but the problem is that I'm not really sure exactly what I'm giving up for that. @EA: Mostly because I have little idea about all things cycle related - I'm all ears though - my main use will be riding on sealed paths/roads (30-40km at a time), occassional fun-race, and possibly (see above ;) very light use on dirt tracks.

I'd ride them all and go with my gut, but since you're asking us again, I'll go with the Jake. The biggest thing you give up is weight, but in reality, the difference between these bikes isn't all that much. You also give up slightly nicer components, but I personally can't tell the difference between Tiagra and 105. I'd get the Jake and some commuter tires like the Continental Contact in 28mm. I ride these tires on a cross bike when I don't need knobs and it's a joy!