The main page in support documentation for widgets and sidebars is here. > http://en.support.wordpress.com/topic/widgets-sidebars/ If you go to that page and click the link for any widget listed you will arrive on a page that clearly describes what the widget is for and how to install it on your blog.
If you need help with attracting traffic to your blog you can start here > http://en.support.wordpress.com/getting-more-views-and-traffic/ and http://en.support.wordpress.com/five-ways-to-get-featured-on-freshly-pressed/ Thereafter you will find the search box is full of tips.
In blogging content is king and marketing is queen. If you write high quality original content and promote it then the result may be an increase in organic traffic, or not. If it’s not easy to locate your content in search engines then there will be no increase in new traffic. Thus, what determines success is two things:
* whether or not your content is found, and
* whether or not the readers who do find it become subscribers.
It’s important to invest time into finding the correct niche for your blog and formulating your goals. It’s likewise just as important to examine your blog in terms of growth models.
In the final analysis, all bloggers need to focus on creating relationships with other bloggers by leaving meaningful comments on their blogs, and by encouraging “organic” traffic that translates into a faithful blog readership for your own blog by responding to the comments you get.
(1) Don't play hide and seek with search engines. WordPress.com makes search engine verification easy. The easy to follow step by step instructions for registering and verufying your blog with Google, Yahoo and Bing can be found in the WordPress.com Support Documentation at the Webmaster Tools link. http://en.support.wordpress.com/webmaster-tools/
(2) Search engine optimization, is the strategy and process of increasing the amount of visitors to a site by making structural changes to the site and the content in it that result in the site ranking high in search engine results. The higher a site ranks in the results of a search, the greater the chance that that site will be visited by a user who has been using a search engine to locate material of interest to them.
(3) There are twenty five steps all bloggers can use to increase targeted traffic to their blogs. The steps are found in this post and you will find they are internally linked to tutorials http://onecoolsite.wordpress.com/2009/01/15/twenty-five-steps-to-increase-blog-traffic/
Hope this helps.