RISC World itself is a solid resource, but instead of beating a dead horse with the same content only branded or discussed a different way, below are a number of solid resources.
Bleeping Computer has a collection of freeware software and useful guides and tutorials to choose from.
Fancy a conference or attending a con of sorts with like minded people? Defcon is the place to be, featuring some of the brightest individuals in this industry.
Hak5 is a great webshow put together by a group of IT nerds. The word nerd being the greatest compliment we could give. They cover a variety of topics rannging from networking to DIY mods.
EDB is a collection/repository for exploits and vulnerable software. It’s a pen testers paradise and a great learning ground for security professionals.