Question about memory finding.

Hey,I'm pretty much new at memory finding/reading,I've been trying to do it by myself until now,I decided to seek help here because I am somewhat confused.

I know how to find base memory address in Guild Wars and I've found out that 1b4 is the offset for "skill id".However if I use base memory address and 1b4 offset it gives me the skill I AM casting.How do I make it so it displays the skill id my target is casting?

I've tried pretty much every possibilty with my "knowledge" but I couldn't figure out how to see what skill my target is casting.I would be really happy if someone could help me out a little.

I have found some offsets,which may lead to solving my problem.But I have another newb question,how does everybody find offsets and list them properly? I know how to find offsets manually with cheat engine but it doesn't look like they do it manually and they do it so fast(including offset names) like it's nothing.

For example how would someone be able to find "offset id" in Guild Wars?