I have macros for all my jobs except white mage.
You won't find a guide on them really since majority of ppl will just tell you "macros in combat are bad" and if you pursue it further they become enraged for no reason.
I use macros because instead of having 9 buttons to push I'll combine the ones that can be combined together to make 1-2-3 buttons.
My monk went from 16 buttons down to 5 buttons for damage attacks.
I macroed fan dance into my dancer's buttons so everytime fan dance is up itll cast itself automatically without me having to push a button.
I macroed my dark knights attacks so I only have 3 buttons, 1 for melee, 1 for range and 1 for aoe. With the shields and stuff combined into 2 other buttons so I just have 5 buttons I need to push to tank.
Its so much easier then having so many buttons, but people hate you if you do it because they are haters for no reason.
Macros follow a 1 second design meaning ur macros can only be in full seconds. 1, 2, 3, 4 seconds before it will start the next skill.
So if my skill speed is 2.5 then I need to macro the next ability to 3. Don't forget to account for server lag, which might make ur 2.5 actually a 3.5, but it varies you can test them to find out what works best.
My alternative to using macros for skills was to just not use the skill. Basically anything over an 8-10 button range and I'd just not push it because really who cares.
So using macros for me means instead of not pushing it, the macro automatically pushes it for me when its ready so I think thats better. Also I seem to do alot more damage now then before so people don't really complain to me when I'm in a group.
Anyway, they are really useful, but I couldn't find guides on it so I had to work it out on my own. Makes the game more fun for me since I'm not always looking at what buttons I have to push and getting hit by everything
Also like to add I got the idea of macroing skills together from the PVP buttons where sometimes they do 2 skills together, which really made alot of sense.