A bike wheel rim can usually be repaired if it's only slightly out of true. If there is a more serious 'dent' in the rim, then it will have to be replaced. People often leave the task of trueing a bike wheel to their local bike shop, but once you know the procedure it's easy to do at home. You will need a spoke key and preferably have a wheel truing stand. If you don't have one of these, you can put together a makeshift truing stand by lashing a pencil to your front forks.
This is a long guide, so you can choose to either watch the entire video above, or follow it in smaller chunks by clicking on the individual steps below.
Steps to Check And True A Bike Wheel:
There are two types of fixing for a front wheel. Hexagonal nuts threaded on a solid axle, or a quick release skewer system that runs through the centre of a hollow axle. If the wheel has a hub brake or a hub generator there are some extra steps.