Running a Node
Why run a node?
You do not have to run your own node to get started with Flow. You can use the Flow Emulator locally to test your smart contracts and web apps. There are public access nodes available, here is the information to get started, Access Nodes.
Running an Observer Node
There are community access nodes available to use, but they are rate limited. Alternative to an Access node, anyone can run their own observer node. This is a good option if you want to have untrottled access to current flow blockchain data.
Setup
First make sure your node has the needed resources, here are the requirements, as per the Observer Node Documentation
Running
For highly used apps with lots of user activity, it might be necessary to run your own observer node. Here are the step by step instructions to run an observer node. The benefit is that you don't have to stake FLOW and you don't have to register your node. Also, already mentioned you have untrottled access to the blockchain data.
Observer nodes does not need to be staked. Transactions are relayed to an access node upstream.
Running an Access Node
If you want to run an access node, you will need to stake FLOW and register your node. Here are the step by step instructions to run an access node. There are benefit to running an Access node.