I disagree. Taking a peek under the hood is the easiest way to get started, but definitely not the best way.
There are hundreds of themes out there and dozens of theme-designers, all with different organizational styles. By dissecting and modifying someone else's theme you take on their organizational structure and you also have a good chance that the theme you start with is using an obsolete themeing protocol, and thus won't install properly using the new litestep. Also some modules have odd commands that you can't figure out just by the name of the command, so you may try to modify one thing on the bar and spend 3 hours figuring out what config file has what command you need to change because the thing you need to change may not be very obvious.
If you just want to make this one theme and never go any further than that, you can skip the rest of my posting, but if you want to start themeing seriously, the best way is to start from the bottom and work your way up. That will leave you with a more thorough understanding of how litestep and the modules work together, your theme won't have any extraneous or doubled commands, and if you want to modify something 2 months down the road you'll know where to look to change it. Also, by reading the documentation for the modules you consider using for your theme, you'll find a lot of nifty features you may never have thought of so you'll end up with a more useful, interesting theme, that is tailored to what YOU want.
Check out
http://lsdocs.shellfront.org for a bunch of really useful info. For someone getting into theme creation, the useful parts on this to make sure to read are the "theme creation" section, the "litestep" section, and the individual module sections.
I know it may seem daunting at first to have all this reading material, but I just got into theming a month or two ago and trust me - you'll save a ton of time by reading the docs instead of just fiddling ;) And for the most part, modules come with text-file documentation so you can easilly just copy the section describing what all the commands do and paste it into a config file, then comb through it and change the associated values.. Piece o' cake :)
Now, in order to make theme manipulation easier for end-users and any theme designers who want to modify your theme, there hs been a protocol introduced called the Open Theme Standard, or OTS. At first glance it seems like it makes your theme more complicated to design but in fact it simplifies it. Some good info about OTS can be reached through
http://ohussain.cjb.net.
For a complete list of modules, see
http://www.shellfront.org/modules-list.php ... unfortunately it doesn't describe what the modules do, just lists them for download. Luckily almost all of the modules have comprehensive documentation and the first paragraph typically states what the module does, so you can just download and unzip the module and check the documentation to see if it does what you need done :)
For what you've described I'd recommend looking at lsBox for the bar anchor (the bounding box that holds all the bar functions). Can't really go any further in advising on specific modules as I don't know what you want to have in the bar.
Anyway, hope this helps! I assume if you've read this far that you are in fact interested in starting to actually create themes instead of just modify someone else's, so welcome to the themeing community! :D