... I'm looking for step by step guides on how to rank a e-commerce site, however I have a feeling that such thing does not exists...
You may or may not find a guide specifically on ranking an e-commerce site, but you don't necessarily need a guide specifically for it.
The way you need to promote an e-commerce site for the search engines is basically the same as how you would promote any other site.
Start with onpage factors. Make sure that you're script is generating proper metatags. It's important for the script to create title, description, etc. for the home page and customized tags for each of your category and product pages. Give a detailed product description for each product so there will be some content for your visitor and for the search engine to index on. Include some detailed content on your entry page and category pages as well for the same reason. Use keyword alt and title tags to all your product pictures. If the script is capable or has a plugin capable of it then make sure to use permalinks that include keyword titles for all your pages.
Then for off page promotion do the same things as any SEO guide you find will recommend. Build backlinks!!!
A few specific things to do when promoting an an e-commerce site are:
- Use a keyword tool to determine the best low competition longtail keywords for the niche you're targeting. As much as possible use those phrases as anchor text when making you're backlinks.
- Start by making links on as many bookmarking sites as you can for you're main page.
- Then go on social networking sites, search for groups and pages related to you're niche, join and post a link on those pages (include a comment including your keyword phrase when you post the link).
- Then write some articles about how useful the products your selling are and give your link as the best place to get them. Post those on article directories as well as create some free blogs (blogger.com, wordpress.com, etc.) and post the articles on those blogs with backlinks to your e-commerce site.
- make a slideshow video showcasing your products with a salespitch for your site and post on youtube. Include your backlink and short presell pitch in the description for the video.
After that you just need to keep building backlinks the same as recommended in any SEO guides. Blog commenting, profile links, forum sigs, etc. Do these kind of backlinks to the article directories, free blogs, and even some of the bookmarking pages as well as making backlinks to your main site. In fact if you move from relevant manual backlinking to automated mass backlinking you'll be better to concentrate a higher percentage of that effort backlinking to those secondary pages.
As time progresses continue doing all those steps for you're main site, and also for select individual product pages.
Not really a very detailed guide, but hopefully it'll help to get you started (and steer you in the right direction to find more information).
Good luck.

irate: