Settle down, advanced settlement placement.
Its time to discuss once again the crucial art of placing your two starting settlements.
First and foremost, consult the guide on settlement placement, there's a whole section devoted to that and for good reason. It can make or break your game, and it can provide for some very interesting matches. Check back here again, after you've gone through the placement guide.
There is a habit which I see many new players practice, namely placing one of their two starting settlements on a port. It's not advisable to do this, the reason being you penalize yourself with one less cell for rolls to land on.
Unless you're landing on a 2:1 port, you will want at least 9 points on the last settlement you place, otherwise your progression in the game will slow to a crawl.
Placing your settlment on a port works against you in two ways, one it limits your productivity early on in the game and you limit where you can expand.
The second point to consider would be to place your settlements to hinder your opponents. It's extremely evil, and downright mean, and you probably should avoid it. But then again it's just a game right, and some people will do anything to get ahead in a game.
When placing your settlements you should first focus on how that settlement helps you achieve your goals, blocking them from their resources or expansion routes is just gravvy.
It's early on in the game where you can deal the most damage in hindering your opponents. Building roads and settlements and closing them in.
One thing to consider is if you're going for the longest road, connecting your two initial cities means that you need one less brick and one less lumber card to get the longest road, it also means that you could potentially have a road 15 segments long. This rarely happens but the potential is there.
The last piece of advice in relation to settlement placement is to diversify the numbers you're settlements are on. While having your settlements on 6s and 8s is quite simply put, awesome. Having both starting settlement son 6 is a big gamble. If alot of 6s are rolled, then you're going to do great, however, on the off chance that noone are rolled, the game is going to be very boring for you. You'd want to avoid this by first placing on a 6 or 8 and then to grab another 5 or 6 numbers to start off with. Otherwise lady, you might be hit by a train of badluck and miss out on development early on in the game.