The website is just the beginning...after that's built, you'll want to get people TO the website to learn more about your services. But yes, the website should be where you start.
You can use a service like Squarespace or Wix to build a simple, yet robust, website. They have very affordable plans that start at around $10/month and shouldn't take you too long to build.
From there, you can add on robust tools like Eloqoa or Marketo, to help with lead sourcing. But for the short run, a simple contact link or contact form should work.
Make sure you also set up Google Analytics on your site from the get-go. That can help you learn how people came to find your site, which then influences any possible SEM (Search Engine Marketing, probably Google Adwords) strategies. If you service a specific location, Adwords is robust enough to reach those potential clients in the area you'd like to target.
Questions like these are right up my alley. Let me know if you'd like to set up a call to go in more depth; I can help you build a plan of attack and may even be able to help execute on some of it too. Good luck!