TaiG released an update for their iOS 8.1.1 jailbreak tool. The latest Taig version is v1.1 with that and the new TaiG version has most awaited English interface. TaiG is the only jailbreak tool which capable to jailbreak iOS 8.1.1 at the moment and they have also claimed their tool will be worked on iOS 8.2 once it available for public.
Please refer our detailed TaiG jailbreak article with guides, video tutorials and troubleshoot section. You can use Taig to install Cydia on any iPhone iPad or iPod running iOS 8 through 8.1.1. TaiG is currently works on Windows platform. You can run with a virtual PC within MAC if you are a MAC user.