Started playing the trial of WoW last week and decided to upgrade to the battlechest. The battlechest includes a free month it says. Can I continue with my level 20 from the trial. I didn't want to mess anything up by installing if there is a set of steps I have to take to continue from my trail character.

Weird, I bought the battlechest and I didn't get a trail - I did buy it in GAME though, maybe it's an online only thing

I started playing the free trial and then bought the retail version. I am asking if I can continue my character from the trial version with the month offer I got with the battlechest.

You should be able to. Im pretty sure that's what my brother did when he upgraded his account.

I am upgraded and using my character. No worries.

Yes you can. Just apply the 1 month free to your account you made for the trial. There are no "trial only" accounts, its just a normal account that had a trial period activated on it.

I couldn't , but I am not sure though.

Anyone and their mother could sign up for a free trial, you don't have to buy anything, just visit he website and download the game.

yes, you can continue your character.