Read the user manual. It's one of the most expensive software in the SEO Toolkit and gives very poor results when compared to other tools which can be bought for much lesser price.
I'm going to have to disagree with you on this one; the amount of forum profiles that I've created and indexed for churn and burn sites with it on my dedicated server will blow your mind. xxx,xxx nullfo
you can try this: https://www.youtube.com/user/XrumerSchool/videos?flow=grid&view=0 and this: https://www.google.com/search?q=xru...F-8#q=xrumer+video+tutorials&safe=off&tbm=vid
Read the manual, check out the forum itself. Dedicate some serious time to not only learning to use it, understand why it is doing what it is doing. Amazing tool.
Never used it but I've heard lots of good things about it. I imagine it takes a while to master though.