require help on first theme: make index look like single post

Hello,
I’m creating my first theme for WordPress. It’s going to be very simple, but I’m kind of clueless at making themes since this is my first. I have a few things I need to do and I need just a little direction (possibly some sample code or methods/functions to use) for them.

#1
First of all, I want my index page to show ONLY the most recent post. That means, when you go to domain.com, it will look identical to domain.com/2006/08/11/most-recent-post.php

Right now, my only way to make that work is to go into WP Admin > Options > Reading > Show at most 1 post.

I’d like a better way to do this please because I think my way will cause some later problems, maybe like the ones below.

#2
As of now, I can get it to show a link to the Next and Previous articles, ONLY when I’m on the single post (domain.com/2006/08/11/most-recent-post.php) but not when I’m on the index. I’d like these links available on the index as well — this ties into #1 where the index will show only 1 post.

#3
Right now, when I search for a term, the results page will only list the most recent post containing the term, because of the 1 post per page mentioned in #1 above. I’d like the results page AND a category page to show a bunch of results (let’s say… 10), not just 1.

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That’s about it. I’m sorry if you think this is too much for me to ask help for. I’d really appreciate any help you can offer and thanks a lot in advance to anyone that can offer suggestions/help/etc.

BTW, I have plently of experience with XHTML and PHP, just not WordPress. I’ve been reading the docs, but they confuse me a bit since many functions look so similar.