As some of you may have seen already, I have somebody making me a theme for my new HTC Diamond. I've done as much searching as I can between being at work and in studio so I'm coming to y'all for help. I know NOTHING about putting stuff on your phone. I didn't know about tweaks until maybe a few days ago, and I definately don't have the technological smarts to figure them out on my own. So I have a few minor questions to ask and you can either respond by simply telling me what I need to do, or a direct link to a page that would help me out would be great.
1.) What kind of software do I need to download onto my phone in order to actually tweak my phone? Is there software out there that I plug all this information into or what? If so, where can I find it?
2.) I'm having somebody make me a theme as I stated earlier (they're being paid for it) and I need to know how exactly I place this theme on my phone. Like I also stated earlier, I'm not smart enough with this phone yet to understand exactly what y'all are doing to really customize your phones. True noob right?
3.) I'd like to extend the battery life on it and I saw some people talking about tweaks to do this earlier, where can I find these and how would I actually put them on my phone?

I know my noobness (is that even a word) is probably almost annoying to some of you that are clearly brilliant when it comes to doing this kind of stuff. I've done a lot of searching but I can't seem to really find the basics in terms of how you all are even doing this. I have no idea what .cab is or manila or anything along those lines. Heck, we can use this thread as the official "Custom For Dummies" thread if we have too. I just need some real help, and I don't have the time to devote reading into many threads on the matter. I really hope y'all can help me out. Thanks and sorry so long.
Kodak