You have two choices.
Option 1 is the preferred option. However a word of caution here. You'll have to provide a copy of your entire RH project source to the translation agency. As they will have to work with RH, make 100% sure that they know RH and are familiar with the file / project structure. There are loads of translation companyies around so choose widely. Unfortunately I have not had my content translated (yet!) so am not in a position to comment on a good one. No doubt someone else will chip in here.
|The RoboColum(n)||@robocolumn||Colum McAndrew|
In addition to Colum's excellent tips, you might also want to take a look at Ben Minson's article in the Adobe Developer Center.
Managing Localized Adobe RoboHelp 8 Projects
Adobe Certified RoboHelp and Captivate Instructor