Quick crash course off the top of my head.
*take your time with territory picks. It's the most important turn of the game. A decent starting out guide for picks can be found here. http://wiki.warlight.net/index.php/Strategic_1_v_1
*One thing to look for is picks that work together to allow you to take a territory faster than you could otherwise. Sometimes you can get a first turn bonus this way but be careful, sometimes that can backfire on you. You don't have to go for the first turn bonus but you do have to be aware that its there.
*Don't clump your picks. Try to be spread out and think about where the fertile areas of the map are that you would like to expand to.
*Never start in a wasteland (a bonus that has a 10 stack in it). For that matter you should avoid those bonuses for the rest of the game. Taking out that 10 stack is highly inefficient so only enter a wasteland bonus if it is for strategic reasons. The home key is your friend, you can use it to see where the wastelands are.
First few turns
*Before you do anything else look at the history to see if you know where one of your opponents picks are. If you didn't get your first 3 picks then you know at least some of your opponents starting areas. Use this when planning your expansion
*Expansion is key. You should have your first bonus by the end of turn 2 (this is why selecting a 3 or 4 bonus is usually better to start out with) All things being equal it tends to be a good idea to focus on the bonus that is least likely to come into contact with your enemy. Keep taking territories and keep growing.
*Some helpful matchups to remember with 16 percent luck:
4v2 is 100%win
3v2 is 79%win
2v1 is 100%win
7v4 is 98%win
*Some matchups to avoid like the plague:
2v2 is 12%win. Yuck.
1v1 is 19%win. Don't.
*obviously coming into early contact with the enemy can throw your expansion plan out the window but if possible still try to expand even if it's slowly.
*The analyze tool is your best friend (don't tell the home key I said that) Use it often to determine if an attack is profitable. It is also useful to determine how many defenders you need to leave in order to make a territory safe.
*Always try to know where your opponent is. Most importantly, do your best to estimate their income. This is key when planning your strategy. Never assume the enemy has less income than you.
*Fight in their lands, not in yours. If possible, take the fight to your enemy. If his bonuses are threatened and yours are safe more often than not you will win. This is why it is important to accurately estimate where your enemy is, so you can plan your expansion to bring the fight to your enemy while keeping your bonuses secure.
*Sometimes a lost battle is a win. Just because you didn't get the territory doesn't mean you shouldn't attack again. Check the history to see the losses incurred. If your income is roughly the same as his and he lost 14 while you lost 10, attacking again can be profitable (there are oodles of exceptions to this rule but the takehome point here is to consider favorable attrition when planning attacks.
*Speaking of attrition, try to avoid stopping a runaway stack. If you find yourself facing an unstoppable force, for example you are confronted with a 20 stack on an undefended front and you have an income of 10. It is rarely the best course of action to defend the front with your 10. Not only will they die but they won't even get to kill that many bad guys. Better options is to launch a counterattack somewhere else where the opponent is weaker.
*the order of your orders matter. Remember that you can adjust the order of attacks. be aware of this and be sure to place important attacks or transfers first and attacks from places you might be attacked at last.
Phew! That got a little away from me there. Anyhoo that's just the tip of the iceberg and there are numerous exceptions to all the bulletpoints. Keep in mind I'm certainly not the best player but these basics should help separate you from the other beginners.