There is a built in process or you can build one in a simple workflow. You will also want to use the approval pages for the transaction type that you want to approve.
Here are the steps that I normally take:
1. Build workflow, keep it simple, maybe 2 or 3 states, and transfer from one state to the next on approval or approval button. Be sure to set field values to approved once the user clicks the approval button.
2. Setup the approval page, Point the approval page to the created workflow
3. Setup a custom view using a saved search.