All reputable Web Design Agencies should have a set of basics that come with any website purchase. Web sites generally aren't cheap, so it's important to make sure you're getting the best possible service.
Free Quotation - A free consultation/quotation is your starting point. You wouldn't pay someone for a test drive, so why expect to pay for an agency to run through what they can offer? It should be built into their costings in the first place not yours. You want a clearly broken down, detailed quotation. This works for both sides, you know exactly what you're getting and what the final outcome will be. Limiting the amount of last minute 'surprises' is essential, even if it means possible taking longer to agree on the terms.
Schedule - Give me somewhere to log in, where diseño web barcelona I can see the current state of play. In fact, send me the schedule when I confirm my order. I want to know what the plan is, and I want to know when I need to get my content ready. There are plenty of project management tools that let you do this for clients. These are generally secure areas where you can log in and view an updated chart of progress, as well as any changes to completion dates.
Process - Tell me whats going on! As a client, in more cases than not you won't have experienced the process of designing/building a website... often it can all sound quite technical and a bit scary. Obviously you need to understand how it all works, and you don't need it to be complicated. A simple old skool flow chart will suffice - this isn't a schedule - this is a simple document which explains at a glance who is involved, what they do when they are involved and what part you will play. Most of us like surprises but not in the form of piles of unexpected work.