This is a question many people ask themselves when they're about to build a website. 

I learned the hard way in the early days, but luckily I don't have to do that anymore. 

It’s very important to think beyond just the surface. 

What to look out for: 

1. Choosing a platform: Choose a scalable platform (such as Odoo) that can grow along with your ambitions. Avoid systems that you’ll outgrow quickly. 

2. The Partner: Choose a development partner who understands your business, not just a coder. Communication is essential. 

3. Integrations: Consider in advance which systems (accounting, inventory, CRM) need to be integrated. 

4. Budget: Be sure to factor in costs for maintenance, hosting, and ongoing development—not just the one-time development costs. Thorough preparation for the back-end processes is half the battle.

If you have any questions, please ask them here and I'll answer them.