You get them naturally. You offer exceptional content, people notice, like your content, and post about it. You can also find forums and blogs in your niche, and publish threads and content that includes links to your site. If you are polite, and offer value to the discussion, the owners of the blogs or forums will usually let your comments or posts stay. You can use social bookmarking sites, such as twitter and digg, and stumble upon. Get people excited about your site and they will link to you. You can also purchase advertisements. If you focus on very relevant, very relates sites, I recommend buying a few text link ads. You can also purchase reviews and blogposts with your links in them. These are just a few methods you can use to get people to link to you without having to link to them. These are many others. Be creative, and offer good content, and links will come.
hi, here is no thumbnail rules that This much links are good for outbound and this much links for inbound, but you can maintain one level, which is as per search engine algorithm, try to read articles, blogs and reviews on limitation of inbound and outbound links in website and hope you will get good answer from them, But seriously, here is no thumbnail rules regarding this matter, As per my view keep one level.