i want to create a email subscription page

Try looking for a suitable plugin.

where is your email list?

You could make a simple form:
http://wordpress.org/extend/plugins/contact-form-7/

To collect the addresses

Then either manually add them to your list, or do something using

http://wordpress.org/extend/plugins/contact-form-7-to-database-extension/

Which stores CF7 entries in the DB and allows you to access and do stuff with the data

the best way to build a mailing list is to have auto responder and there are quite a few on line and they give you html code that you can use to create sign up form.

look for a plugin may be there is one around
I just searched and have not used it try it out see if this works
http://wordpress.org/extend/plugins/wp-responder-email-autoresponder-and-newsletter-plugin/