The first time you sign up for AutoEntry you are on a free trial automatically. Simply go to www.autoentry.com and select which group you belong to (Accountants & Bookkeepers or an SME). The Free Trial link is right there on that page.
Even if you buy credits you will still receive your free trial credits on top of your purchase.
And that's it! Subscription or not you're signed up and ready to go!
See here on how to upload your first documents.