Adjusting to aerobars
I read somewhere (I think it was Zinn, but I can't find it right now) that the angle of the bars is a comfort thing and makes not much difference from an aero standpoint, and your seat should be level. You likely need to move your seat forward to reach the bars comfortably. My old rig was an old Cannondale roadie with aerobars; I ended up buying a forward seatpost (Profile & Nitto make these) to get to the correct position.
Trial & success is the only way to find your best set-up.
No manual can tell you exactly what settings are right for your physique.
I switch from my road bike with clip-ons to my TT bike with aerobars every day or so at random and according to the weather. Don't want to mess up my new baby, heh.
Some days I ride the MTB. It's all good.
I can still adjust my position on the bike and ride with the two different geometries, which suggests that the body has a wide range of tolerance for position.
I know I don't stay locked motionless in one position on a 6 hour bike ride.
PoC
Know what I told Santa I wanted for Christmas? Spring.

Trying until you get the most confortable position is the way to go.
I got a clip-on aerobar and went to my LBS to install it. After that I went to get a professional fit with a local expert. Tha worked fine for a while. On my long ride this morning I arrived to the meeting place and found out that I had left one of the pads at home, so I rode most of the time with my right arm on the "unpadded" aerobar. It was so comfortable, even with the feeling of the velcro in my arm, that I am lowering my handlebar. I had never been able to ride 60 miles in the aero position.
It is only trying until you find what works best for you.





I've had my eye on a few used tri bikes lately but just couldn't come up with the extra cash to purchase one so I opted to put aerobars on my roadie. Picked up a pair of Carbon Stryke aerobars from Ebay and had my LBS install them for me. I got to the bike shop 2 min before they closed, so didn't have time for them to re-fit me to the bike and make adjustments. When I got home I took the bike for a spin and it's obvious that I need to make some changes to seat position and the bars for optimal comfort.
I'm sure there's a thread here or somewhere else where this topic is discussed; if anyone can post a link or offer their own thoughts, it would be much appreciated. I'm planning on fiddling with this all weekend to get it as good as I can.
At a minimum, I'm thinking that the seat needs to be tilted a few degrees downward. Perhaps moved back slightly too. Also, I'm not sure what angle the bars should make, relative to the ground. The LBS installed them at a slight upward angle. Should they be more horizontal? I suppose this is a matter of preference to some degree.
UPDATE (10 min later)
OK, I googled it and found tons of info......I'll see how it works out