It's simple really, say your going through the hex editor and your find a bunch of "FF" starting at 900000. Now when you make a script, start it with 0x900000. This will tell the game to place your new script into that area of free space.
Sorry about that, you seem to be a good member; I should have know. Yeah, Zel is probably one of the best fan-hackers out there, he knows WAY more than I, but he is busy while I am not.
Wow! That's way too much to insert into the game, as the GBA series is not ment to hold that much data. Sorry, but only like 2-3 extra pokemon can be added to Ruby/Sapphire; and even then you may run across problems. If you want the shinou pokemon, your going to have to erase some old pokemon.
Alright, to make a warp, if it does not already exist on the map, do the following. First, go to "events view" and scroll down on the right, until it says "Event manager". Look at the list now. Find where it says "Amount of Warps" and change it to the number of warps you will need. Don't worry you can always change it later. Now do you see the button on the bottom that says change events? Click it. A window will pop up that reads "Events" click ok, and it will find available space to put your new event. Click the button that says "re-point" and your done making a warp. It should appear in the top left-hand corner. As for changing it all you have to do is click it. So lets say you wanted to warp to inside of Mt. Moon. You would look at the numbers beside Mt. Moon on the list, which happen to be 1.1. The first number represents the "map bank", while the other represents the "map". So change your warps "Map bank" to 1 and your warp's "map" to 1. Now we need to find which specific warp will your warp go to. The entrance number is "event number 3" so change your warp's "warp no:" to 3. Congratulations your warp now takes you to the Mt. Moon entrance. Hope that helps, if you need me to explain further send me a PM.
I know it seems like a little much at first, but you'll eventually get the hang of it. Just remember to always back it up and try, try again! Don't give up, just picture what that glorious hack will look like in the end! :D
You must make a script for it, and insert it. I believe I answered this in depth a couple of posts back, look there if you need help.
There are only a couple of completely blank maps stored in the game. Otherwise you'll have to erase some old maps.