With xrumer you wont be able to do posting/profile creation straight away. You are likely to need many mods and a decent xas file to be able to post successfully.
The mods can cost alot if you go out buying and not many thread/forums helping on xrumer as much as other software since xrumer has being used mainly with mods and many hours of work from the user to create decent list and other files.
I will not suggest because this is totally spamming tool.
Umm, do you know what kind of site you are on?
scrapebox - just scrapes and posts on blogs (dead method) - xrumer actually makes unlimited forum profiles and posts so much powerful and also has a built-in scraper called hrefer
scrapeboard - buggy, no auto captcha, you will quickly spend $400 in captcha cash, unlike xrumer that autosolves captchas and isn't buggy at all