I started my own blog about SEO tips and Tricks and currently using just free WP themes and after getting the review done, it has been suggested that i should have a better theme, I do have little knowledge of Photoshop so can design a theme for myself but can any one tell me how do i go about converting it to a WP theme
Assuming you know programming, slicing images and what-not, you can grab a theme framework like Thematic and style it mostly w/ CSS (maybe a little customizing depending on your needs). You don't need to code a theme from the ground up. Who is suggesting your theme could be better and what is there expertise? Doesn't look too bad to me. Then again, I'm not a designer...
What you can do is use a Free theme that fits your niche(there are many out there) and after 5-6 months, go for a customization theme but as for now your blog is new and once you get some visitors, you can think of getting a unique design.
First of all, i would like to support the people who suggested to have a better theme. I do believe that there's always a room for improvement. And there's a big difference (for me) in using a free theme from a custom theme. And about your question, the first thing you need to do is make / provide yourself a web design (.PSD) but if it's already coded on HTML/CSS then everything will be easier. You just need to divide the html page to php files. 1.] header.php 2.] index.php 3.] sidebar.php (if there's sidebar) 4.] footer.php 5.] single.php (for posts) 6.] page.php (for pages) 7.] archive.php (for categories, archives) 8.] 404.php 9.] function.php Of course what i said above are the core files (If I miss anything, please feel free to say it). But there are still more like search.php, comment.php and etc. I strongly suggest that you google (html/css to wordpress theme tutorial) for more guides. Or you can use the default template of wordpress as your guide. Hope this helps
If it's soemthing you're not going to do often I would outsource the work otherwise it's a large learning curve!
If you want to do it yourself what you can do is start from a wordpress framework and customize it into what you want. Check out: http://www.smashingmagazine.com/2009/05/27/wordpress-theme-development-frameworks/