Step 1: first go to the nexon site(p.s make sure its in internet explorer)
Step 2: Follow the image and click the signup button!
Step 3:Your Now at the Signup Page Follow The Image to Fill it out
Step 4: when you complete the form press the accept button shown below
Step 5: after pressing accept you must verify the information
Step 6: After you signed up click this icon on the left hand side.
Step 7: Once on the maplestory site click this button on the left.
Step 8: you will now be at the terms page click okay to continue
Step 9: Click the button i listed as pick me to continue on.
Step 10: fill out the form and be sure to verify the login.
If the login is good to use then you will see

However if the login is already in use you will see
Once you have a good login press okay with the rest of the form filled and there you go people now you have a Jms login.
Credit goes to PhotonPhazer this will be hlere.. maybe till we get a stratiges section =D
Newer one? (i cant really find out at the momment but i read some comments from the pass few months and some guy has a newer one ill post that one up
1. Go to the Nexon Website and click the big green button! http://www.nexon.co.jp/JP/Page/NX.aspx?URL=Home/Index
2. Fill out the form as you see fit.
3. Accept the Agreement.
4. Verify your info(if you want) and Hit ok! (hint: its the circled one)
5. Click on the MapleStory image circled here to go to the JMS website to register.
6. The remainder of the process is pretty simple as it is part english, part japanese. Don't ask me why they did it that way, they just did it. If you need help with this part, it is text, so copy it to babel fish and translate it.
Once you finish, Enjoy your new NexonID and JMS!
Note: This can help.
www.jms.cjb.net