1. Press the wake button
2. Slide the unlock button
3. Press the Home button if you previously were in another application, if not, skip this
4. Press the Phone icon
5. If needed, press the Contacts button. There are Favorites, Recents, and Keypad buttons as well.
6. Press the name of the contact you want to call
7. Hit their number

To Lock the iPhone:

Press the sleep/wake button

To Unlock the iPhone:

Press the Home/Sleep/Wake Button, then drag the slider

To swtich off iPhone:

Press and hold the sleep/wake button, then drag the slider which will appear in red color