You can really use any of the SEO plugins out there – Joost de Valk’s one is pretty popular as is the All in one SEO pack. Your’e milage may vary, so find what works for you.
You should remember though that an SEO plugin by itself will not improve your pagerank. An SEO plugin just facilitates presenting information to a search engine in an appropriate way for search engine consumption – for example find tuning your title tags or meta descriptions.
SEO is really all about content, and I did have a look at your blog and it seems a lot of your posts of very minimal written content, you could probably spend some time making sure you write some nice easy to read content that will rank for the keywords you are targeting with that post. Be sure to make full use of excerpts and meta-fields.
It really just takes a lot of practise and time to build up your blogs reputation. If you product good content that people want to read — even a badly coded site will rank — although not as well as it should.