So far you're getting good advice... I too am a Napoleonics fan and Metal Modeles, Pegaso and Romeo are top notch... I also have had good luck with Andreas Miniatures for Nappys. Benito, Art Girona and Masterclass also make some nice Nappy figs... Some of the On-line retailers list links to other manufacturers.
I also used Citadel paint for years but as soon as I tried Vallejo (and to a lesser extent, Andreas) acrylics, I completely dropped Citadel... Even the metallics!
You're absolutely right to start with the simpler pieces... Lancers are beautiful subjects. Stay clear of the hussars for the first couple... they're enough to make you want to toss your brushes in the fireplace
As for reference, there's tons of material out there... for French Imperial subjects, for my money, I've found nothing better than Lucien Roucellot's "Napoleon's Army 1798-1815". Hundreds of great colour plates and fantastic uniform and equipment details, covering all arms of French army.
Good luck, this is a great era for figure painting and modelling and there are tons of PF members who are very knowledgable on this subject and more than happy to help... just drop an PM if you have questions
Colin