We usually try to include various types of files like pictures,documents,pdf files etc.For the picture files,you can directly upload the file to site and embed in your blog using <img> tag.
For word document files(.doc files),
you would need a Browser Plugin to do this .This will be really helpful for those who have no MICROSOFT OFFICE installed in their system or without a valid license.
For word document files(.docx files),
There is a new Firefox plugin that allows you to open any docx file without any other software like MICROSOFT OFFICE 2007. Using this plugin, you can view docx file in original format and it is available for both Windows and Linux.
For Adobe pdf files(.pdf files),
Suppose,you have a online .PDF document and when a user clicks the link, you want it to open in the same window.Then include the following php code
<iframe id="myFrame" style="display:none" width="500" height="300"></iframe>
<input type="button" value="Open PDF" onclick = "openPdf()"/>
var omyFrame = document.getElementById("myFrame");
omyFrame.src = "myFile.pdf";
You can do the same with asp.net with following piece of code
protected void Button1_Click(object sender, EventArgs e)
Response.ContentType = "application/pdf";
Remember to add head to the Response stream and set inline to display the pdf file in the browser.