I've read most magazines at some point, and buy 2-3 per month. I go through phases of getting different ones consistantly, and then they start repeating themselves too much, they change their design, or they put the price up. :shrug:
I like reading them though, as I do a lot of bus travelling, and of course there is always the porcelain throne to kill time on.
When people talk of magazines they always talk of 'you can learn it all on the internet', and yes you probably can, if you know what you want/need to learn. But the magazines are about more than that, there are images/portfolio's to view there is image appraisals, interviews, guides to photography, guides to image editing, gear reviews, gear comparisons, software reviews. They may have something that you may have not known existed, such as a bit of gear or software that you may never heard of, or a new technique. Yes, they same information may be on the internet, but how do you know it exists unless it appears in front of you at some random point? :shrug:
Yes, if you are just buying a mag for what you can learn about the technicalities of photography, then maybe it may not be that cost effective. :shrug: Some of the publishers do photography books covering a lot of what has appeared in the mags for about £9-£15 if you just want all the technical and theory stuff about photography. :shrug:
The thing about learning things from mags, is that they all cover pretty much everything over a year, so after a years subscrition you'd know quite a lot imho. Some magazines like Practical Photography have had a really good basics/bootcamp series over the last couple of years to have a structured learning of the basics, with interactivity with the mag, and their website.
What I wouldn't say that using a camera mag for generally is learning the basics of image editing. Yes, some of them do cover it, but some of them seem to feel that while they can show the basics of photographic technique pretty much annually, they cover the basics of image editing and then start to go on to more outlandish photoshopping, as they must feel that they can't repeat those types of basics as often. :shrug:
Like I said, I've read almost all of the mags, and there are a lot of them, about 16 the last time I counted.
At the moment my mags of choice are DigitalSLRPhotography and Practical Photographer, but I have the odd different one if they have something interesting in it. :shrug: Normally if you go into a shop and browse through them, one or two catch the eye.
And as has been said, you can get some very good offers to eaither buy them cheaper, or get them cheaper plus a 'free gift'.
If you go to some of the magazine's websites there is a lot of useful tutorials and guides available to read.

Some of the websites are very basic though. :bonk:
http://www.advancedphotographer.co.uk/
http://www.amateurphotographer.co.uk/
http://www.thegmcgroup.com/pc/viewCategories.asp?idCategory=698
http://www.bjp-online.com/
http://www.dcmag.co.uk/
http://www.dphotographer.co.uk/
http://www.digitalslrphoto.com/
http://www.dslruser.co.uk/news.php
http://www.f2freelancephotographer.com/
http://www.nphotomag.com/
http://www.photoanswers.co.uk/Home/
http://www.photoforbeginners.com/
http://www.photographymonthly.com/
http://www.professionalphotographer.co.uk/
http://www.photopromagazine.com/
http://www.whatdigitalcamera.com/