Human Website

Hi Nancy, thanks for your question.

Inbound links are external web pages linking back to your website. E.g, abc.com links from 123.com. While outbound links are external sites that you're linking to. E.g, abc.com links to 123.com.

Inbound links are definitely much important than outbound links. Inbound links determine your site authority and page rank for Google to evaluate your websites and rank high on search engine. According to SEOmoz Search Engine Ranking Factors 2011, inbound links are the most important factor SEO consultant have to do in order to rank high on Google.

Even outbound links, it is not something webmasters have to worry about except.

1) Reader satisfaction
- Provide your readers with and in depth information about your topics.
- Provide your readers article sources

2) Build relationship with other companies and bloggers
- Helping other companies and bloggers for their link building strategies.

You should put more time on inbound links rather than outbound links.

I would advice you to carefully choose companies that selling links (regardless of inbound or outbound links) because you don't know how they do it for you and where they submit your sites links. E.g, Google hates link farms. If those people submit your sites links to link farms. It will affect your search engine ranking.

My advice for inbound link building is invest money in Wordtracker or MajesticSEO to analyze your competitors' links. Both Wordtracker and MajesticSEO already helped you to filter those useless links to Google, so that you can put 100% effort to only quality links to avoid wasting your time.

Below are few links that link to Google for more information about inbound and outbound links. (These are outbound links).
Hope I answered your question!

thanks very much for your full length information
i follow your tips and get this

http://www.majesticseo.com/reports/site-explorer/summary/ebooksm.com?oq=ebooksm.com

in fact i could not understood the right meaning of these information