Let's see, I'll try to cover everything as best I can and hopefully it'll help you with your pursuit of knowledge as well as your website.
1. Facebook/Twitter Images and links
There are plenty of sites that have these and plenty of ways to implement them. Just taking a quick look at your site I feel you could easily add these along either the left or right side of your page, as a fixed bar of icons (can't think of any good example sites to link for this). As long as you can access your site's source code you'll just want to work in a bit of custom code in the header template file to get these social icons/links appearing on your entire site. Below is a rough draft of what it would be. You would need to of course find appropriate facebook, twitter and other networked site logos to upload and use.
<div id="socialLinks" style="position: fixed; top: 50px; right: 0px;">
<a href="http://www.facebook.com/YourFacebook"><img src="/images/facebook_icon.png" alt="Facebook" /></a> <br />
<a href="http://www.twitter.com/YourTwitter"><img src="/images/twitter_icon.png" alt="Twitter" /></a>
</div>
2. Adding a blog
There are tons of choices for blog software available today and plenty of ways to go about creating one. Obviously you want this integrated in to your website and so you'll need to find a package that you can install on your webhost. Many webhost provide auto-installers for various things like blogs, eCommerce, etc. If you don't have anything to do that automatically then there will be some extra steps involved (downloading a blogging software package, uploading it to your site via ftp, running some installation scripts and filling out necessary information for database access, etc).
There is some useful information on blogging softwares here: http://blog-software-review.toptenreviews.com/
Other than that it really comes down to what you have available and what your preference is.
3. SSI/credit card protection logos
This is really similar to what I talked about in #1. You can use essentially the same code to place the desired logos in a specific location. There would be adjustments more than likely, such as using 'absolute' instead of 'fixed' for the position and possibly changing the number values to move it to a location of your choosing. You also might not want it on every page, so it wouldn't be added to a header file in your site's template.
4. Improve web rankings
When you want to improve the ranking of your website on many of the popular ranking sites/systems there is only so much you personally can do. One of the more important things is SOE (Search Engine Optimization). You'll want to make sure you use proper meta tags for your site to list its content, keywords and such as well as make sure all links on the site are search engine friendly.
Also submitting to various online directories can be useful. The open directory project is an example of this.
Also getting links to your site on social networking platforms can help with the rank.
In the end it's mostly about getting your site well-intertwined with as much of the web as possible. Website ranks from places like Google typically look at how many times (and from where) your site is linked to. That isn't something you can really control yourself as it typically has to come from other reputable pages (for instance a news homepage vs a personal facebook page) and so that depends on others wanting to share and link to your site.
