If you are selecting a company or professional to help you with your SEO efforts, don't accept any unsolicited offers, especially through email. Unsolicited email offers for help with your search engine optimization is more likely to be a scam than any legitimate company. Just like in the off-line world, businesses advertise for you to go to them and not the other way around.
Put a sitemap on your webpage. A sitemap is a page that easily links to all available pages on your site, and more importantly how to find them. This feature makes it easier for the search engine spiders to navigate your site. The fewer clicks it takes to find or get to a specific page the better.
Leave comments on other peoples websites on a regular basis. Take your time and find the articles that have a high PageRank page, and leave comments on these. This will help you improve the PageRank score, and may have other people coming to look at your site more often as well.