Thank you for your posting. Click here for our FAQ explaining what is available with the trial. You can create as many emails, events, surveys as you want, but it is limited to 10 contacts.
You will want to save the contacts into lists in your account. You can create as many lists of contacts as you would like and you can even create different varieties of lists with the same handful of contacts. To create a list, click the Contacts tab of your account and use the plus icon next to "lists" on the left of the page.
Here are some directions on how to add contacts to the list. You will want to choose this list to send to when you are scheduling your email!