Welcome to the community.
Bid management is a very broad subject and the implementation vary as per the campaign goals.
Go through the information on the links below, which will give you basic information about bid management.
Choose your budget and bids - https://support.google.com/adwords/answer/2375454?hl=en
Choose a bid amount - https://support.google.com/adwords/answer/2471184?topic=22217&ctx=topic
Understanding bidding basics - https://support.google.com/adwords/answer/2459326?hl=en
Hope this helps,
To add to Deepak's great answer, here is a link to an article I wrote about crafting a Bid Strategy that works for you. The important thing about managing Bids is to choose a strategy that works for your goals. In order for AdWords to be profitable for your business you'll need to acquire leads/purchases at a cheaper rate than your cost to you.
I suggest you first figure out what a Conversion is worth to you and what your profit margins are, and then work backwards when selecting Bids.
I'd also like to point you to three bidding resources AdWords has -
- AdWords Conversion Optimizer - For advertisers with AdWords Conversion Tracking setup.
- AdWords Flexible Bid Strategies - A variety of Bid Strategies that AdWords can help automate.
- AdWords Automated Rules - Set Bidding Rules based on certain criteria.