the procedure is in the manual which you can get in the sticky that yamagod has posted.
for the cam tensioner, you will need to lift the head off and it might be a good idea anyway, so you can check valves, rockers for wear etc
oil should be ideally on the top line, but between is ok, are you using the correct grade (20w 40 in usa, 20w/50 in uk) and are you checking AFTER just resting the dip sick ontop of the casing (ie not screwed in!)
drewps