hey guys,

im very new to this, this is only a very recent new interest being part of a course that im enrolled in.
anyway, i was wanting to build a small guitar amplifier, i have the speakers set up and take input from a 1/4" trs, very easy to do. i want to build an amp that outputs a 1/4" trs so i could use them together.

i was going to adapt the little gem shown here:
http://www.runoffgroove.com/littlegem.html
i think someone posted this before, however im having trouble reading the schematics
i did a bit of building off schematics a few years ago. but iv lost the memory since.
its to my understanding that power must flow in a circuit, however in these schematics
it doesnt show where the negatives go (for audio input, battery, ect), does the negative go
to the ground and is the ground symbol those little downward facing triangular arrows?

i was wondering if i could build this even simpler, is it possible to build an amplifier with just an audio input, 9volt and an audio output? or do you have to have either some 386 chip or npn?
1 last thing, does anybody have any links to even simpler amps that i could build. around the 1watt range with simple to follow diagrams?

thank you for your time