Prospective team.

[Ultimate Charizard]

Basically my net has never been that reliable so ive never seriously trained for online play.
If it gets working though i may be able to get up and running especially now im on Platinum. Ive never been much of an EV trainer (not even sure what they are other than what EV stands for) and natures dont really mean anything to me either.

This is what im training at the moment... (just past the second Gym)

Kadabra - Inner Focus
Gentle Nature

Buizel - Swift Swim
Timid Nature

Zubat - Inner Focus
Hasty Nature

Onix - Rock Head
Hasty Nature

Grotle - Overgrow
Naive nature

The last member of my team is a ?? at the moment, it just has Doofy, my HM slave in there for now.

I am thinking of Changing Zubat for a more Sturdy Poison type, maybe Skuntank or Toxicroak. The only ones i dont want to add to this list are the team i trained in Diamond. (Lucario, Infernape, Luxray, Gengar, Garchomp, Golduck)

Any suggestions or advice on Moves or team fine tuning?

The only moveset im thinking right now is for (what will be) Steelix with Thunderfang, Icefang, Crunch and Earthquake.

[Poryhedron]

I'm no expert on what's best to use for competitive play, but I can help by explaining natures and EVs.

Each of the 25 Natures grants a 10% boost to one stat, but deals a 10% penalty to another. Your Kadabra, as a Gentle pokémon, has heightened Special Defense but lowered physical Defense; your Buizel, as a Timid pokémon, has heightened Speed and lowered Attack (which is a great nature for a special sweeper); your Hasty Zubat and Onix have heightened Speed and lowered Defense, and your Naive Grotle has heightened Speed and lowered Special Defense.
Competitive play is tight enough that a 10% difference can easily mean victory or defeat. Choose what you want each pokémon to be best at, and what each pokémon doesn't need to be good at, and then find the Nature that suits them and catch or breed until you have the right Natures.

EVs are all about how you train. Let's say two humans are training to be athletes. One of them does mostly weight-lifting and the other does mostly jogging. The first is going to be a lot stronger than the second, but the second is going to be a lot faster than the first. When it comes to pokémon, the difference is in which enemy pokémon you train against. A pokémon tends to get good at the things its opponents are good at. For example, if your Kadabra mostly trains against Staravia and Rapidash, it'll pick up a bunch of Speed EP and gradually get faster than other Kadabra with its same Speed IV.
EVs have a maximum value of 255, but they only help your stats in multiples of 4, so anything higher than 252 is a waste. In addition to the cap on each EV, a pokémon can only collect 510 EP total, so you can only max out the EVs for 2 stats. Get 252 instead of 255 and you'll have enough EP to boost a third stat just a tiny bit. Some advanced trainers, though, plan out more complicated EVs than just maxing out two of them.
At level 100, an EV of 252 raises its corresponding stat by 63 points, so EVs are definitely crucial to success in competitive play. As with Natures, know what your pokémon need to excel in. EVs are a little different because you have more freedom in which stats you raise and don't have to choose a stat to harm.

[Ultimate Charizard]

Damn....thats REDICULOUSLY complicated lol.

Im starting to think the Dumb Luck method might suit me more lol.

[Rossymore]

I understand that strangely. Now I know how these things work...it's clear to me now. Thanks Poly!

[DarkestLight]

Its not as bad as it may seem. but it IS time consuming. Heh, Pory didnt get into details about the ways to accelerate EV growth.