It's tough to ask SEO questions because you get so many different opinions. At least you're on the right track as far as building "quality" inbound links. Avoid the easy tips and tricks like submitting articles and hooking up with blog networks. Quality SEO is a lot of work and you want to be properly informed before you start mucking around with links that can seriously harm your online potential in the future. If you want to know the difference between a good link and a bad link and good SEO advice and questionable SEO advice, reach out to me. To answer your question; you want to get links from sites that Google already trusts. If you're a landscaper, you've got to find sites that are already ranking well for your keywords and reach out to them to see if there is an opportunity for those sites to link to you, or reach out to the sites that are linking to your competition, but you need to know if the link you’re leaving is helpful, harmful or useless in regards to your objective. Google likes to see quality references back to your site; nothing that looks paid or easily setup through a network of blogs. I hate it when people suggest blog networks for links. These are identified quickly by Google and quickly become useless links back to your site or even worse, links that tip Google off that you are trying to go about linkbuilding the wrong way. Sure they may work for a while and you may think you’re going to enjoy great rankings for the life of your business, but you can’t build a business off of blog network links. It can all go away overnight and that’s not something you want to wake up to. Don't be too quick to act on questionable advice. Do your homework and seek the advice of established consultants you can trust with the future of your business.