If you don't want to use the equipment manager, you can use some /equip or /equipslot stuff in macros.
I want a "spam SS" button, and I never want to SS with my dagger. I want to equip my dagger when entering stealth and equip my sword when leaving stealth, all automatically. Here's how I do it:
On my main form action bar, I've got a button with this macro:
/equip [equipped:dagger] Cruel Barb
/cast Sinister Strike
and if I ever have my dagger equipped, it makes sure to swap me back to my sword.
I also have this macro, to enter stealth with:
/cast Stealth
/equip Sentinel's Blade
Then on my stealth action bar, I have a macro like this:
/cast Stealth
/equip Cruel Barb
which I use to cancel stealth if I don't want to be stealthed anymore.
What iaccidentallytwink said about equipping weapons causing a GCD is kinda correct; there are some actions you can take while also equipping weapons, and others you can not. I seem to recall the "stealth and switch weapons" macros don't work if you switch the order of the /cast and /equip commands.
I can vouch that these types of macros work, since I use them.
I actually use slightly more complicated ones because I switch both my mainhand and offhand when stealthing, but the idea is exactly the same. (I use buzzer blade OH in stealth to increase my crit rating for Ambush)
Macro trinket slots are #s 13 and 14, for top and bottom. When building your healing macro, don't forget that the [ITEM]Minor Recombobulator[/ITEM] does not cause GCD. :-D