How to access ITunes Store in foreign country

It depends on the country you will plan to open the account on.

For example, if you want to open an account on US or UK, you could select None as payment method. Payment methods you can use in the iTunes Store, Mac App Store, App Store, and iBooks Store, same website for UK.

If you want to open in in Spain, you don't have this option. ¿Qué métodos de pago puedo usar en el iTunes Store?.

Best option is to open any websites I post before, go to the bottom of the page, select the country you want and check available options.

You can browse any store without an account. If you scroll to the bottom of the iTunes Store home page, there is a link for Change Country. But without an account, you won't be able to purchase anything. See jherran's answer about options for obtaining an account.