I am going to be hooking up a lot of stuff, and would like to add a nice extra fuse box, so that I don't have to keep splicing into the 12v constant in my ignition harness...are there any other options?
I have already installed an alarm, car starter, and power door locks....

 

get a fuse block, run a heavy gauge wire to the main terminal, label the circuts and you should be all set. I really don't understand what you wanna know.

 

is it good to keep tapping into the 12v constant, like shouldnt i use a seperate fuse box for all my accessories, i have heard of people running an extra fuse box with the cigarette lighter wire

 

The only real reason to use an additional fuse block is if you are drawing a lot of power, you need the space, or you want to make it a little neater. I would not run the constant power off the cig lighter though. Thats not that big of a fuse 20 amp if I remember right. That means if you have 15 amps of accesorys running and you use the cig lighter your gonna blow a fuse. The best way to do it is gonna be to run a 0 gauge if you need 150 amps, 4 gauge if its gonna be under 100 amps, wire from the positve battery terminal with a 150 or 100 amp fuse very close to the battery. Run that wire to where ever you want to mount the fuse block, and connect all your accesorys to the fuse block with individual fuses and wiring that are going to handle each accesory.