In order: Cianwood City, Mt. Mortar, Vermillion City, Route 13, Bill's House. You're welcome.
in whirl islands.... i think
Route 30
you go to and find misty and then battle her at the gym them go back and suicune shuld be their
Magnimite envolves at Lv.30
well suicune jumps around the johto region and after you have beaten the elite four you can go to the kanto region and suicune will appear around there and on the last time you go to cerullean city and up go as far as you can then where bills grandpas house is go along and suicune is there
it depends on what game you have, in heartgold and solesilver it is on top of the bell tower
if im not mistaken, u have to go through diglett cave, via moving snorlax with ur radio pokeflute music.
all you need to do is beat feiry feild then lighting feild then you get to fight suicune then go to fight ho-oh and then go back and fight suicune but have a freind bow its easyer for suicune to be your freind
After you beat all of the kanto gyms, go to cerulean city and go to where you saw misty with her "date". Suicune will be waiting there.
Well, if I were you, I would go into a room with Suicune in it. (but the Suicune could be low level). I did this and I got one. I hope this helps.
If it is anything like Crystal you have to go to Ecruteak City. There you go into the burnt tower and you meet Suicune for the first time. You then leave and continue on your journey. After you have gathered all the badges you go back to Ecruteak and enter the building with the three wise men. They will allow you to go through. There will be Entei, Raiku, and Suicune. Suicune will come up and battle you.
Go to Fuchsia City and then to Route 15 (If you have already seen Suicune on the water just fly to Cerulean City). Next go to Route 25 and (if you have already fought her) go to where you found Misty. Then you will see Suicune and Eusine will come and talk to you. After that just talk to Suicune and battle it.