Since it's your thread, can I get your advice on a decent hybrid bike? Google has really been my only guide on this so far but two in particular have taken my attention. One is a Ltd Edition Carrera Sunbake (?) selling at half price (£190) at Halfords, and the other recommendation I came across is a Specialised Crosstrail going for about £240 new and perhaps £150 second hand for one in reasonable nick. From what I can gather Specialised has the better reputation here, although I don't know a lot about Carrera.
I'm still not exactly an expert in afraid. I'd certainly go for Specialized over Carrera. You'll find Halfords do some good deals in terms of equipment levels but they use cheap materials where possible to keep costs down so I'd avoid Carrera which is essentially their own brand.
Specialized, Trek, GT and to an extent Boardman are good names for hybrids though you pay a premium for the name on the latter.
One feature I'd definitely look out for is the ability to "lock out" the front suspension. I have a GT Transeo 2.0 with this feature and the switch is mounted on the handlebars near to my right thumb. On the lower specs (3.0 and 4.0), you have to reach down to the top tube (crossbar). I thought it was a bit gimmicky at first but it's brilliant. You see, having front suspension is all well and good, it certainly makes the ride more comfortable but when you're pounding your way up a steep hill, the front end "bounces" slightly so energy is lost. Locking it out makes the whole bike rigid so that power transfer is more immediate and efficient. There's some b***ard hills between my home and place of work and trust me, it helps!
Perhaps my biggest piece of advice would be to stretch your finances a bit. You say you want a cheap bike just to get into it but, from new you generally get what you pay for and if you go too low, you'll want to upgrade in no time.
I paid around £650 for mine through the CycleToWork scheme and some colleagues went for cheaper bikes, one even bought a lower spec version of mine. They have ALL upgraded since. Could turn out to be a false economy.
In truth, you'll be struggling to by anything decent new for under £500 over here. Second hand could be the way to go but I appreciate it's a minefield when you don't know what you're looking at!
I'd also think carefully about how you will really use it. I went for a hybrid as I thought I'd use it on-road and off, taking in canal towpaths and the likes. In reality I ended up just using it entirely on the road. Eventually I bought myself a full-on road bike and it makes a huge difference.
Good luck, I love biking, there are bike paths all over town here and I can get just about anywhere without ever having to get on the road.
Don't get me started on so called cycle paths in the UK!
Here's 50 metres of road painted green for you, now you have to go up onto the path, now off again, now we're coming to a roundabout so you're on your own for a bit. Cycle path comes back, cars parked all over it. Here's a bus stop, not to worry, go up on the pavement and behind the bus shelter, through the broken glass then hop back off. Don't mind these potholes and grids, cyclists deserve to be in the gutter...
Our roads are too narrow to be adapted now, you really are best just sticking to the road and riding near to the middle of the lane so cars don't feel obliged to squeeze past and force you into the curb.