Many time when we came across some website we like some fonts or some colors so much that we want to replicate the same on our blog as well. So one solution to this desire is to keep trying different families of fonts and colors and may be if you are lucky you can get one matching to the desired one. but its very time consuming 
. For Not so geek persons like me differnet addons are available which we can simply install in our browser and vola !!!!! the entire internal schema and css classes are in front of our eyes. you can simply select the information you want and can replicate in your website . below is the example of my blog www.digitallyalive.com.
For me i have install firebug , its indeed the best add on available for firefox users , for internet explorer users a variant firebug lite is available.
installation steps
1 open tools->Ad-ons from the Firefox main menu .
2 Click on the get add on option and search for firebug.
3 Click on inline code finder for firefox and then click add to firefox.
4 After installing this a new link should come up in your tools menu as firebug.
5 Click on open tools->firebug->open firebug , a new window should pop up.
6 Now select tools->firebug->inspect element.
7. you can hover mouse pointer to any object on the web page in the firebug box you can observe the css settings as well as html code for that object. below is the example for www.digitallyalive.com .you can see in the html box that what font size and color and fonts i choose.
for internet explorer,safari,opera you can use extension of firebug as firebug-lite.
I hope this prove helpful .
