What can I do to make my wordpress blog more "browsable"?

It has passed some time since I have started this blog… In the beginning when there were only a few posts it was really easy to find any of them. But now, with more and more post each day this is getting harder and this will get much worst in the future. I have tried various solutions but I am far from being satisfied with the results. So what can I do? I am placing this open question to my readers to help me with this issue in case you have better experience with wordpress or with blogging design in general. So if you have any ideas just let me know. Thanks in advance.

What is the problem again?

1. How to easily find old posts… A blog is by definition meant to be read chronologically. But what if you are looking for an older post that is no longer on the frontpage? This happened for sure to me while looking for some old post and in the end I finished up hitting the search button. But I have done that knowing that the article exists and what to search for. Normally a reader will not know that…

2. Search engine hits… I often see peoples coming from search engines (google rules by the way with 99,999% of the referrals) and they just land of a different page. I see the perfect match for what they are looking for in another article, but they will leave once they see the page they landed doesn’t match their interest… Hmm… annoying.

What I have tried so far?

1. Related articles: this seemed to be the perfect solution for all the problems. But it doesn’t seem to be giving the expected results.

2. Tags: I have added tags to extend wordpress categories and hoping that this will enhance the ‘browsability’ of the blog.

My only other idea is to place somewhere in the sidebar the tag cloud. Hopefully this will help… But what else can be done? If you have any bright ideas I would really like to hear them.