Some people frown on torrents because they are mainly used to share ripped CDs, DVDs or software. But you can find almost anything on them.
One STRONG word of advice. Buy the best Antivirus software money can buy before you download anything from a torrent site. I recommend ESET NOD32 or Kaspersky. It's even a good idea to use torrent only on once system in your house that you don't care much about (eg. an old laptop) Don't rely on crap antivirus software like Norton or McAfee etc.... Scared yet?
1) Download utorrent (google for it) and intsall the program
2) Go to one of these "
top 10 torrent sites" and search for the software you want. Sort your results by the most Seeders and DO NOT download anything that has been uploaded less than two days ago (new uploads are likely to have viruses and will quickly be identified by users a dangerous)
3) download the torrent file (a small file with details on the "main" files you will end up with)
4) let uTorrent automatically open the small torrent file and watch/wait for the files to download.
If you can't find what you are looking for on one site, check a few others. Unfortunately one of the best torrent sites (btjunkie) recently voluntarily shut down.