local sites and external cooperation

Hi,

I am currently administrator of Mozilla.cz website and forum.mozilla.cz 
support forum. Last week we've received an offer for cooperation with 
one of the support forum projects (pc-help.cz). My question is, if there 
are any limitations or recommendations for cooperation with such 
projects (bidirectional promotion, possible forums connection etc.)?

Cheers,
-- 
Michal Stanke