Welcome to the forums. To answer your question, yes you will be charged for international texting. A way around this would be to use instant messaging such as Yahoo Messenger. Instant messaging is not part of your texting plan, so you will need to have a data plan for sending instant messaging. If you do a lot of messaging back and forth to other countries, then the price of a data plan might be worth it. Just thought I would give a tip.
....Instant messaging is not part of your texting plan, so you will need to have a data plan for sending instant messaging.
Slight correction - if you have a texting plan, a bundle or unlimited, and Mobile IM, the IM's are considered text messages, and you DON'T NEED A DATA PLAN. The only data involved is to download the Mobile IM application initially. It came pre-installed on my phone, and I have unlimited texting on my plan, (Family Select, NO DATA) and there is no charge for using Mobile IM to text - this would be an excellent way to text internationally and avoid texting charges. You can use Yahoo Messenger, AOL Messenger, or Windows Live Messenger.