Root and/or flash ROM on Haier Haipad 8.0 (PAD821)
First, have you tried to search for this device on http://forum.xda-developers.com? They should have got the ROM and the ROOTing method for you. 

Note: Never try to ROOT or install a ROM from someone you don't trust! Again never root the device when its still in use, because Rooting the device would remove the warranty of its! You might brick your device too. 

You can try to search for the ROM by the name. Secondly I know the good rooting software, search for Bin4ry root! They will root you device, you can follow steps! hehehe, you must see the Note I provided before continuing the process.

By that software, you can first Root the device. Then check for the CWM support for your device on their site. Or you can Google it to find the best solution for that phone. After installing the CWM, you can easily install a ROM, but again, becarefull while installing the ROM, you might brick the phone.

Good luck, Cheers!