In reply to ste_d:
Brakes can be a pain to bleed - look on YouTube for "how to" video for yours. Try forcing a full measure of fluid in from the caliper and/or keep doing the "pull quick/release slow" trick on the brake lever until no more air bubbles appear. Failing that, take the bike to a bike shop to get it done for you.
You can get a full set of pre-bled Clarkes ones from Chain Reaction Cycles/Wiggle/Halfords for just over £40, for example, if you can fit them yourself. Other options available on eBay.
Alternative would be replacing the hydraulics for a set of mechanical disc brakes if you want something really low-maintenance.
By now, you might also want to think about getting the bottom bracket serviced/replaced if it's rough, replacing the gear cables if they're rusty and replacing the tyres if they're perished.