Depends on your area mate. If you join the Met the wage is 22k start at the moment with an extra 6.5k in the form of london weighting/allowances. The pay scale has just changed with the Winsor report so that you reach roughly 36k after 7 years instead of 10 years, which it was before (36k is the max for a PC). Check out this link for pay:
http://www.police-information.co.uk/policepay.htm You might also want to check out listentotaxman.com if you want to work out your salary after tax/NI/pension contributions.
I'm focusing mainly on the Met here: for the foreseeable future you can apply externally, which means you do not have to be a special/PCSO to join anymore. There was recently a recruitment drive over Summer and there is another due in Autumn. However, you must obtain a "CKP" to join the Met now and I believe this will be rolled out to most forces when they recruit. CKP stands for "Certificate in Knowledge of Policing" and various colleges in the UK are offering it. The course lasts for roughly 6 weeks, but a HUGE part of the course involves self studying. The certificate remains valid for 3 years (or 4 years if you are a special/PCSO) but of course it does not guarantee you entry into the police and before taking it you must make sure you meet the police criteria - it costs around £900-£1000. When we hit 2015, who knows what the recruitment will be like - but this info is for the rest of 2013 and 2014.
I'm going to be blunt and say this: if you find yourself thinking that the money is the only thing that attracts you to a job in the police then you will most probably fail or quit if you got in. The job is very, very demanding and stressful with huge restrictions on both family and social life. Will you be able to cope with the shift work (involving lates/nights) and cancelled rest days? Or dealing with a suicide/RTC (road traffic collision) and telling relatives what has happened AFTER dealing with deceased bodies? Or dealing with aggressive people on the street who are drugged up/drunk off their face? It is a lot to think about and it's something you need to research deeply.
In my opinion, again being blunt, one should not have to ask the benefits of becoming a police officer, as these should come naturally and in my opinion a career in the police is a calling. However, despite the negatives of being a police officer of course there are many benefits. The chance to make a difference, help victims of crime/people in their time of desperate need, lock up criminals, work as part of such a close knit team where you can always rely on your fellow officers, the chance to specialise (eg. Dogs, Firearms, Mounted, Marine, Air Support) and promotion (sergeant/inspector etc.) ((although in recent times specialising/promotion has become harder)), REALLY doing something different every single day, getting to see the country at all times of the day/night and how it differs etc etc.. the list is endless.
You really need to look around online - check the force websites, policecouldyou.co.uk, the police fed website, UKPoliceOnline forums - there's so many different things out there. Also I'd recommend heading onto Youtube and looking at as many police videos/TV programmes as possible - this will give you a real idea for what it's like out there (although don't be fooled by the TV shows, there IS a LOT of paperwork
). How about go to your local police station and ask about work experience or talk to your local safer neighbourhood team about what it's like? I did 2 weeks WE on 2 different boroughs and it was really informative. Also don't rule out uni/apprenticeships if you aren't completely sure about the police - if for whatever reason you did leave/didn't join the police you need a back up plan.
I hope this has helped, and my apologies for being rather severe at times. Please PM me if you need any more info - I am intending to join the police and have researched it for the past 3 years - all the best