I am new to SEO and have read many posative things about using header tags (h1, h2, stc.). Well, I now want to know if it is ok to modify the header tags. Can I use CSS to make the h2 tag look like the rest of the text on my page. What I mean is will it affect the effectiveness of the tag its self?
It's perfectly ok to change the size of header tags with css, but that doesn't mean you can use them more because they are smaller. Only use (1) h1 tag per page. You'll get different opinions about number of "h2" tags, but I personally don't use more than 2 per page.
Header tags will be treated as headers no matter how we style them Therefore, the following has the same effect as <H2>Hello</H2>: <H2 class="somestyle">Hello</H2> Code (markup):