Estimating is necessary to figure out what the job
will cost you.
First of all you'll need to set up a simple chart of all the details: the items you will need to purchase (i.e. cable, connectors, etc) and their costs. You will also need to add labor cost.
Once you have gathered all your information, you will need to bring your math skills into play and create a document (usually a spreadsheet) that allows you to transfer all this information into a "map" of the job that you and your workers can follow. Refer to chapter 14 of "The Fiber Optic Technician's Manual" for an excellent guide on how to create this document.
Bidding is closely related to estimating, but adds in the profit margin you need to stay in business - don't forget that! If you bid accurately, you will never regret losing a job to a lower bidder, because you know that the winning bid is close to or losing money and that is not the goal of running a business. Bid accurately and you will stay in business!
Knowing where every cable, connector, splice, patch panel, etc goes and the length of every cable is more than helpful. It can help you in bidding, buying, installation, testing, and restoration. After installation, keep test data to refer back to when you have problems. Smart installers understand the value of documentation and understand it can lead to higher bids, but good documentation pays for itself. Smart users understand it too and are willing to pay for good documentation.
Today you can get several great programs that automate the estimation process. They can access databases of costs, aggregate components and do lots more to simplify the process. Evaluate all these products - a contractors trade show is a good place to start looking at them - to see if they meet your needs.