When I started modeling military models I was clueless now I got all this info at my finger tips.My first model was a M4A1 Sherman 76mm gun by Italeri and it was very good if I say so myself.So my question is I just bought the kit mentioned above and it has letters and numbers molded on the hull and turret are these standerd markings or are they markings from the maker (Tamiya).Should I scrape them down or sand them down?

NO,NO, NO, a thousand times NO! These are correct, the original vehicles had these from the castings of the turret (and in some variants) the cast-hull. There are not an addition from Tamiya, they faithfully copy the original vehicles...Jim

Jim's right, just about every piece on a combat vehicle has some type of part or manufacturer number on it. They are much neater than the numbers welded on the turrets and hulls of modern tanks such as M1s. Many US vehicles like the M88 series still have numbers cast into the parts.

Good advice so far!

One thing kind of annoying thing about Tamiya's Shermans is that they have open sponsons (unlike that Italeri kit you built). Here's a link to a handy template to block those open sponsons: http://www.archertransfers.com/WEB%20pictures/ShermanFix.pdf

If you feel like going a bit beyond the box, here's a "tweaks list." for the Tamiya M4A3: http://www.usarmymodels.com/MANUFACTURERS/Tamiya/tamiya35122.html