I just tried your keywords and I was able to generate results - Link hidden: Login to view
Not sure what happened on your end. Kindly try clearing your cache and doing your search once more.
Yes each member can only do 10 searches per day but this will usually refresh 24hours after your last search. Our developers are currently working at how you our members can do more than 10 searches per day.
Sorry but we don't have a guide of some sort on how to use the Research Lab. You can refer to the Link hidden: Login to view
, or to this blog - www.salehoo.com/blog/ebay-market-research
But please feel free to contact us should you need further assistance :)