Airfix can also be good for 1/48 WWII birds.
I've seen both their late model Spitfire and Seafire kits from a few years ago and they are beauties.
Revell Monogram can also be a good choice, they are usually a good balance between detail and price. The cost of some Japanese kits can be very intimidating and if, for whatever reason, the kit does'nt work out, you have the cost hanging over your head.
If your just starting out, you don't want to break the bank on a model that your skills may not be up to.
The only one I'll warn you against is ICM's 1/48 Spitfires. They are drop dead gorgeous kits in every way, loaded to the brim with detail, but definitely not for beginers. Typical of Eastern European produced kits, exact parts location is not outline extensively in the instructions and there aren't any guide pins and holes on the parts to help you line them up perfectly.
Definitely kits to consider when your skills are more developed.
I'd recoment Revell Monogram for beginers, mainly for the afor mentioned balance of price and detail. Most of their kits have sufficient detail straight out of the box to please a beginner. Their kits are also much more forgiving of a beginner's mistakes than some other companies kits can be, this means a beginner can have a chance to undo their screw up and still come out with a good looking model.