Robots.txt for blog?? (Newbie..)

Hi everyone

I have a wordpress blog. Basically I want to make it as SEO'd as I can. I'v ebeen researching and there are a couple things i'd like to ask:

First - I need to know how to make a good robots.txt file, optimised for SEO of my wordpress blog.

Ive just been looking up an example robots.txt to use for my blog, expecting it to be the same as that for any normal 'non-blog' site.

I have seen example robots.txt for wordpress that look different from those on a regular site.

could anyone direct me to one that is correct, or help me out here?

Is this a part of a blog-only robots.txt file?:
"#User-agent: ia_archiver-web.archive.org
#Disallow: /"

Second - I've read about automatic sitemap updater/submitter plugins for my wordpress blog. I thought manually updating and redoing a sitemap would actually be quite a lot of work at the end of the day for a blog - it gets updated and pages added a lot more frequently.

So can anyone direct me to a good working automatic sitemap updater, and any requirements i'd need to use one? Is this an automatic sitemap submitter/updater: http://www.semiologic.com/software/xml-sitemaps/ ?

Thanks very much!
Emma x