To get using Charge you'll need a Stripe account, and connect this our Craft install.
If you don't already have a Stripe account, you'll need to sign up at stripe.com.
Just Testing? Before you're able to take live transactions, you'll need to confirm some additional details on Stripe.com. While you're just testing you won't need to worry about that.
Once you're logged into your account, you can get your API Keys from the Account Settings > API Keys page.
They'll look something like this:
Stripe's API Keys: Stripe keys come in 2 type, and 2 modes. Public and Private, and Test and Live. If you're only using Charge in test mode you can just enter the test mode keys if you'd prefer.
In your Craft Admin area, go to the Charge settings page, either via Charge > Settings, or the plugin list page.
In the settings, you'll see an overview of the current state of the Stripe connection. Assuming you haven't already set your keys, it'll likely look something like this:
Before being able to take live payments we need all those markers to be in a good state.
Enter your stripe API keys in the connection form. That'll look something like this:
Key Validation When you add your keys here Charge will try to validate them with Stripe. We'll let you know if the keys appear incorrect
Remember to configure the webhooks Charge will let you run payments without having the web hook callbacks from Stripe configured, but some advanced functionality will not fully work without it. Anything involving recurring payments, or subscriptions are especially dependant on the callbacks.
With your API keys in place checkout the quickstart guide for the next steps.