I use Tinymce in all my projects but every time I do it I face some problem.
Here is some steps in which you can install it.
1. Download tinymce project from <a href=”http://drupal.org/project/tinymce”> here</a> and extract this into your sites/all/module directory along with your other modules.
2. Download the core engine from <a href=”http://tinymce.moxiecode.com/”> here</a> put this into a your tinymce folder which you just extracted in step one. now it will look something like this sites/all/module/tinymce/tinymce.
3. Now go to the admin/build/module and enable the tinymce module.
4. now go the admin/user/access and give permission to the user who will use tinymce.
5. After enabling go to the admin/settings/tinymce and create a new prfile, and choose the settings.
6. You will require to add some HTML tag in “admin/settings/filters/” go to admin => site configuration => input format now click on configure in front of filtered HTML, go to the configure and add these tag to the “allowed HTML tag” text field.
<code>
<a> <p> <span> <div> <h1> <h2> <h3> <h4> <h5> <h6> <img> <img /> <map> <area> <hr> <br> <br /> <ul> <ol> <li> <dl> <dt> <dd> <table> <tr> <td> <em> <b> <u> <i> <strong> <font> <del> <ins> <sub> <sup> <quote> <blockquote> <pre> <address> <code> <cite> <embed> <object> <strike> <caption>
</code>
and now save it. now you are ready to use tinymce.