Newbie needs help: Ranking and backlinks

Hi,

I'm a newbie and want to ask a couple questions on ranking and links.

First of all, I want to make a post on someone's blog so that I get their link juice. (This is in a blog network). I have seen people do the same thing and they find the blog post outranks their own site for their particular keywords they are trying to rank for. It's the same thing if you submit to an article directory. So I've read to use different anchor text to avoid that happening. If you do that how does that help your site? You wouldn't be ranking for your term right? But does it give you good link juice to your site over all? Does it boost your site anyway as you have the terms you're ranking for on your site? Could someone clarify how the whole ranking thing works?

My other question is on backlinking. Is it worth it to do a tonne of backlinking (such as web 2.0 and article sites etc.) when you can just use one source that gives good backlinks that make you rank you well? You could then save time and move on to make your next site. Would I be losing out on a lot of traffic by not using web 2.0 and article directories? If the goal is to get myself ranked on the first page of Google, do I worry about how many links I can get or just concentrate on the one or 2 that get me there? Guess I wonder again if I'm missing out on the extra traffic but I guess it's hard to tell. I could just as easily have software that submits to article directories and web 2.0 sites but wanted your opinion first.

Thanks,

Cheryl