True, true. First thing you have to do is figure out if you're climbing or diving, by checking which way the speed needle is moving.
- oldman

Look guys, the only thing that is going to tell you for sure if you are climbing or descending is the altimeter!!! The vertical speed indicator or VASI instrument is a "trend" instrument only. I can make the thing show a 1,000 foot per minute climb and my nose pointing at the ground!!! But you can't fool the altimeter, because it does not depend on attitude, just pressure changes as you climb or descending!!!! The only two instruments in the aircraft which will NOT deceive you is the turn and bank indicator and the altimeter. Even the airspeed indicator has "LAG" in it, so you can't depend on it for control of the aircraft.
If the altimeter big hand is not moving and the needle is pointing straight up and the ball is in the cage, the aircraft is straight and level!!!\
Most instruments in today's modern aircraft are electrical driven and they to have their limits of operation, but even at that, they still have some instruments which depend on the "static" port, located on the outside of the aircraft! Locate it and make it a part of your walk around pre-flight inspection.
Most aircraft prior to the 90's, had instrument driven by vacuum pumps or venturi's located on the outside of the aircraft. These too had their faults and limitations, so best get familiar with what is in your aircraft and how it operates, so that in an emergency, you will be better prepared to handle it.
My motto is and always has been: "There are old pilots and bold pilots, but there are no old, bold pilots".
another motto or phase will serve you well is this: the three things you must have, but can never use in aircraft are:
Runway behind you
altitude above you
fuel left in that red truck sitting on the ramp!