Google Policy on interlinking my websites together

I was wondering what's Google's official policy on linking my own websites together, do they forbid it, allow it, allow it as long as it's no-follow, etc.

For clarification i will give both a white-hat and black-hat examples:

white-hat: I'm a web designer who also has several affiliate websites. I designed those websites so i would like to give myself credit by linking from the affiliate website to my professional bio website where people can hire me as a designer.

black-hat: I buy 100 different domains and link each one to the other 99 sharing all the link juice between them. The content of each website abide by Google's policy and isn't spammy , the only thing that's wrong is the fact that i got 99 links to ea开发者_JAVA技巧ch of them and i'm the only one doing the linking.

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First solution - nofollow:

Well, if they are nofollow, I don't see why Google would care.

So, you'd probably be safe with that, if what you want to achieve is indeed giving yourself credit.

But, as for SEO optimization, as you already know, the sites wouldn't benefit much.

However with nofollow, even if you didn't increase pagerank, number of visits to each site should increase (the traffic from your other sites). This also could be beneficial.

Second solution - portfolio site:

There is one scenario which could suit your purpose:

1. Create your "portfolio". A site with links to all the sites you created, as an example of your skills and stuff..
2. Place a link on each of your sites to this portfolio.

Now, you have a page with 100 outbound links, each perfectly legitimate. And each of your sites contains just one outbound link connecting it to your other sites.

This should be fine both for your presentation and for SEO, and you avoided having a link farm.

EDIT: You can find actual info from Google here: http://www.google.com/webmasters/docs/search-engine-optimization-starter-guide.pdf