Files that Google Index:

Web Design Promotion

Alleged Negative SEO Google Ranking Factors

Text represented graphically is invisible to search engines.
Affilates on your website.
Too much keyword stuffing.
Stealing text and images from other websites.
Too many dynamic pages.

What Files Types can Google Index?
Many types of files can be indexed by google. Some of the common types include:
Adobe Portable Document Format (.pdf)
Adobe PostScript (.ps)
Atom and RSS feeds (.atom, .rss)
Autodesk Design Web Format (.dwf)
Google Earth (.kml, .kmz)
Lotus 1-2-3 (.wk1, .wk2, .wk3, .wk4, .wk5, .wki, .wks, .wku)
Lotus WordPro (.lwp)
MacWrite (.mw)
Microsoft Excel (.xls)
Microsoft PowerPoint (.ppt)
Microsoft Word (.doc)
Microsoft Works (.wks, .wps, .wdb)
Microsoft Write (.wri)
Open Document Format (.odt)
Rich Text Format (.rtf)
Shockwave Flash (.swf)
Text (.ans, .txt)
Wireless Markup Language (.wml, .wap)
To make it easy for google to index your pages keep your code clean. Use CSS to call Java script files. Limit images, have a content rich website. Don’t have too many dyanamic pages