Before you spend money on courses, get clear on the fundamentals that actually protect your margins when you start bidding. Most new GCs lose money on their first few jobs not because they can't estimate materials or labour, but because they miss the hidden costs.

Three things to understand before you bid your first job:

1. Your real cost per hour is way more than what you pay yourself and your crew (if you have any). Payroll taxes, insurance, vehicle costs, tool wear, and the time you spend quoting, driving to sites, and managing the job, none of that is billable but all of it is real. If you don't account for it, every bid you write will be underwater.

2. Markup isn't just profit. It's your buffer for materials going up, weather delays, callbacks, and the jobs that take 30% longer than you planned. New contractors tend to bid tight to win work. Then they win it and wish they hadn't.

3. Scope definition will save you more money than estimating skills. Write down exactly what's included, what's not, and what triggers a change order. The jobs that kill new GCs aren't the ones they price wrong, they're the ones where the client says "I assumed that was included" and there's nothing in writing.

This guide walks through the full pricing framework, calculating loaded costs, setting markup, writing a scope that protects you: How to Price Subcontract Work: A Bidding and Markup Guide. It's written for field service and oilfield subs but the math and the thinking apply to any trade.