HELP!!! truck and rookie need timing tips

I just replaced the head gasket in my 89 b2200.
its been pretty discouraging for me because I also did the timing belt and I don't think its correct.
how do I know when my engine is at top dead center?
also what are the markings for TDC? open circle for the top wheel? cut out or notch for the bottom wheel?
one more thing,, do I need to assemble to parts back on completely to fire up this bucket?
any help would be excellent and much appreciated
thanks

This is from another thread:

"The cam gear marked #1 is lined up with the 12 o'clock position mark.

The crank shaft pulley mark is at TDC and at the 12 o'clock position.

The #1 piston is flush with the top of the engine block. (check through the spark plug hole

The rotor under the distributor cap is pointing to the #1 spark plug wire which is at the 9 o'clock position.

If not matching up you'll need to do a timing belt install procedure..."

Check this out too:

Good information and photos:

Thanks bud.