Here I'm going to describe the advantages and disadvantages of  most important Axis planes in Forgotten Battles. Please note that this is only intended as an overview:

Bf109E4(/B) 1940:
When it first saw service it surpassed most of its opponents. It outgunned and outclimbed all contemporary RAF planes including the Spitfire MkIA. Its only drawback is the maintained turn-rate which is lower than that of the Spit and some russian birds (I153, I16). The best tactic is to make use of your superior climb-rate and speed. If your enemies try to follow you into a power-climb they will likely end up floating in the air like sitting ducks. Then jump them from above and see them desintegrate.
Bf109F2/4 1941:
This more advanced version of the Bf109 which was very common at the beginning of the war against Russia is much better in terms of flight performance than its predecessor. It benefits from an automatic prop-pitch system which takes off a lot of work from the pilot. However its armament (especially with the F2) is weaker than that of the E4 but a skilled pilot will also be able to effectively use these planes. The same tactics should be used.
Bf109G2 1942:
Basically this is an upgraded version of the Bf109F4 with a more powerful engine which provides about 200hp more an a higher climb-rate as well as top-speed. Although it is a little bit less forgiving in turns I myself would take it over the F4 at any time. Like some of the F-series planes it could be equipped with two additional MG151/20 (R6) and then used as a bomber interceptor. While the G2 only saw short service with the Luftwaffe it was one of the workhorses of the finnish airforce and was successfully used against the VVS. The Bf109G2 is the last in the series of air-superiority fighters produced by the Bayrische Flugzeugwerke and the first variant to be equipped with the WGr.21 rocket propelled grenades. All later versions have a higher payload due to heavier engines, more armour and bigger guns. As consequence their inflight performance was slightly reduced. Tactics are the same as with every Bf109 plane.
Bf109G6 1943:
This variant is comparable to the G2 but with a different armament and flight performances that are a bit worse. Instead of the two 7.92mm MG17 machineguns of the above planes it has two MG131 13mm guns which can be recognizes as bulges on the top of the planes cowling. The G6 was the most widely used version of the Bf109 in WWII. In late 1943 this plane could also be equipped with the 30mm Mk108 nose-mounted connon which had just entered mass-production. The AS version features an MW50 injection system which powers up the engine output. If you are flying in a 1943 scenario only pick the G6 if you are going to intercept bombers. Otherwise take the G2 because it is superior in dogfights.
Bf109G10/14 1944:
Same as the G6 but with a Methanol/Water Injection System which provides more engine power. Their standard gun mounts are two MG131s and one Mk108.
Bf109K4 1944:
This is one of the last versions of the Bf109 and is basically a faster G10 with reduced maneuvrability. Its top-speed is around an impressive 714km/h.

Me262A1/A2:
The first and most succesful jet-fighter during WWII. Development already began in 1941 and it finally entered service in late 1944. The Messerschmidt 262 has a speed advantage of about 150km/h over the fastest allied fighter of that time which makes it an excellent bomber interceptor for it can just fly past the escort. The massive armament of 4x30mm Mk108s in the A1 is enough to chew up any plane in no time. However its roll-rate is very low and turn fights should be avoided. The weak points of this aircraft are its engines which can easily catch fire when hit. Takeoff and landing is also far more complicated than in any piston fighter but if this bird is finally in the sky it will surely deal out some serious punishment. The A2 version has "only" 2x30mm Mk108s but can carry 2xSC250 bombs under its nose making it a very fast and effective Jabo. Both vesions can also carry the R4M air-to-air missiles which were designed to destroy enemy bombers.

FW190A4:
The second sort of fighter which was in service with Germany in WWII. It is much better armoured and armed than the Bf109 but suffers from poor maneuvrability. However it has the best roll-rate of all WWII fighters. Horizontal maneuvfrability is limited and the plane tends to stall if taken into a tough turn but it's easy to recover. The only way to fight when flying the Focke-Wulff is energy-fighting. Anything else is suicide!
The armament is 2xMG FF, 2xMG151/20 and 2xMG17
FW190A5:
It is about the same as the A4 version but with an additional emergency power system. Higher top-speed but lower maneuvrability.
FW190A8:
An even heavier variant of the FW series of fighters with impressive armour. It has a heavy armament consisting of 4xMG151/20 and 2xMG131. This plane was mainly used as a bomber interceptor and should stay out of fights against other fighters unless it has a clear advantage.
FW190A9:
Very similar to the A8 with the same armament ad armour.
FW190D9:
A high altitude version of the FW190 with reduced armament (the outer wing cannons have been removed). All in all this plane is much better suited as a fighter than any other variant. The 1944 version of the D9 has an increased WEP system whereas the 1945 version has an MW50 injection system.
At the end of the war German engineer Kurt Tank designed a more advanced and maneuvrable evolution of the Dora which was called Ta152 (Ta = Tank).

JAL - Japanese AirForce:
As soon as some of their planes are included I will post some basic information.