you didn't mention what kind of magazines you are looking for.
Usually magazines are available on many sites as almost all trackers have "ebooks" category where you can find all sorts of magazines.
In general trackers torrenday.com, iptorrents.com, scenetime.com and last but not the least demonoid.me and thepiratebay have extensive magazines torrents. But you would find the better variety in elearning trackers like ebookshare.com, myanonamouse.com, bitspyder etc.
However, the best place to look for magazines are nontracker sites where they can be downloaded easily as they have relatively small sizes. For example ebookee.com is the best place.
Hope this is helpful. If yes, don't forget to click thanks