Way too many things to write srox, anyway by before launching, you meant, the site is not live yet or you haven't started promoting it ? in any case, stick to basics and NEVER forget to add fresh content - Rest will follow soon. One tip, Please read this post, I am sure it will help you. The rest should follow up easily.
hi see all the broken links , attached site map, submit it to the main search engines directories and social bookmarking for the more information give me pm.
Check your site well. Check the spelling and grammer and broken links. After correcting all upload and do SEO works to promote ur site
SEO wise, what I usually do it so make sure there are no broken links, all pages are linked properly with proper anchor, sitemap is working properly, meta tags and all. Just the basic things
Before launching it have an on page optimization and KW optimization by doing this, spider will be able to crawl your site much faster .
check your meta tags, url, conent . your url should be a final one. i mean changing the url later is difficult task