Posts comments and topics in forums:
Find out which forums cover your industry or area of expertise. Register with as many forums as possible and put a link to your website each time you make a comment. Post new topics and answer other people's queries, and join in as much as you can. Refer people through to your own website but don't plug your site too much as you might end up being booted out of the forum.
Post stuff on blogs
Find out who is blogging about stuff in your industry and make comments on their blog entries. Use the opportunity to put a link to your site in your signature and make sure you come across as sincere and willing to help others, rather than someone who is desperate to big up their own website.
Get out there and make sure your website is listed in as many website directories as possible, making sure that you're listed in the section that's relevant to your business industry. Select 'add my site' and enter your details. It's not tricky but it does take a bit of time and effort.
Ask bloggers and other editorial websites to write about you
Contact all the important bloggers and journalists in your industry. Send them an email or give them a phone call. Try to convince them of the value in writing about your website.
This is the quickest way of getting links to your site, but it's also the most expensive one. The most important sites to buy links on are those that are in a subject relevant to your own.
Send out press releases
This is one of the easiest ways to generate inbound links. Write a press release about your business/services and include links to your website. Post the press release out to as many free sites as possible, as well as using the traditional media such as newspapers and magazines. Well known press release sites include Prweb.com and pressbox.co.uk
Write articles and post them
Sites such as ezinearticles.com and submityourarticle.com allow you to submit articles to them free of charge. You could use these to write articles about your industry that are of interest to others and then place your details at the end of the article with a link to your website. Make your articles as meaty and debatable as possible so as to generate more interest and more inbound links.
Ask your friends and visitors to link to your site
Most people are happy to recommend friends or colleagues to another website if they have had a good experience themselves, which can be a great source of inbound links for you.
It really is up to you how well received or unsuccessful your website is, based on the amount of effort you put into creating enhanced SEO opportunities for yourself...so get started!