So first, a disclaimer - I knew nothing about bikes at all until I started looking for suitable London bike last year. So all my knowledge / advice comes from the perspective of a self-taught but until recently, total newbie.
That said, what I ended up doing / buying was a spectacular success
Originally I thought I wanted a hybrid - previous bike I owned was a mountain bike, was unsure about the drop handlebars on racing / road bikes, so a hybrid seemed like an obvious choice
After lurking in the bikeradar forums, lots of singlespeed chat caught my eye so I looked into them in more detail
Fundamentally, what you get is a really simple bike to run / maintain. No gears means a simple, decision free riding experience. It also means fewer delicate parts that can break / go wrong, and less time / effort to clean / maintain. As a bike newbie, that really appealed
Gear ratios vary, but you'd be amazed how versatile a single gear is, especially in london traffic, when your journey will likely consist of short sprints between traffic lights. You don't want too high a gear because you'll want the acceleration and climbing power, but simply because single speeds are more efficient and typically lighter than a geared bike, you can get away with a higher gear then you would expect
To get an idea of the variety of bikes / prices available take a look at Evans' online site... you’re looking at £300 for a ‘basic’ new bike. A funky brand like Charge will cost you a lot more
Suggest you then find a decent bike shop in London and talk to the staff there. The best bike shop in London I know of is next to London Bridge
They have a huge range overall, including some singlespeeds, and they will let you test ride
If you like the experience, search ebay for singlespeeds, but ignore ‘fixies’ or ‘fixed gear’ unless you have a highly developed brave or curious gene
There are also bikes for sale listed on the bikeradar forums here:
And there’s a dedicated single speed forum here
Word of warning – if you thought a videogaming forum could be alien and inhospitable to newcomers, you’ve not seen anything yet. I’ve only ever lurked on either.