No, it would've been easier just to give you a number. But since they didn't, you'll have to go sailing. THere are site online that will help you tune your rig. Each rig is a little different, and sails are cut differently, so it needs to be "customized". Most just crank them down for 25 kts, and call it a day.
The short answer, check to make sure the mast is in column, and then go sailing. If the leeward shrouds go slack in less then 15 kts close hauled, then they're too loose. If they go slack, tighten the leeward shrouds a turn or two. Then tack and tighten the other shrouds. This will get you close.
There's A LOT MORE to it than that, but unless you're really concerned with performance, I wouldn't worry about it. But rig tension makes a huge difference, even on stiff masts. Most cruisers have the shrouds too tight, but it's better to error on the stiff side, than the loose side.
Merit 25 # 764 "Audrey"