This is the first post in this forum, and I choose to cover the first issue a person will encounter if he/she decides to play NL SNGs online. What SNG should you sit down at? This is a unique type of table selection because all opponents sit down at almost the same time, so you have less information availible to you than you have at ring games.
However, there is still lots of information avaiblible. First, what site should you play at? In my opinion, there are a couple of answers to this question, depending on your stakes level. If you have an online bankroll in excess of $200, I would recommend playing party poker. This is a result of the easy accessability of Party SNGs, and the lower than standard quality of play. However, if your bankroll is smaller, DO NOT play the Party $5+1 SNGs -- the rake will eat into your profits and make your risk of ruinmuch greater. For small bankrolls, I recommend sites like Royal Vegas Poker. These sites offer $5+0.5 SNGs and even $2+0.2 level SNGs. Another viable option is Pacific Poker. Pacific is your best option if you are the kind of player who will only play one SNG at a time, because the quality of play is terrible. Be prepared to wait quite a while for your SNG to start.
NL holdem SNGs are very profitable, but I think your edge can be maximized at the limit holdem SNGs, because at these tables your edge as a result of tight play is much greater than in NL in my opinion. More mistakes are made at the $10+1 Party limit SNGs than the NL SNGs.
Some sites offer SNGs with 5, 6, 10, 20, or 30 players. Excellent strategy posts abound in other forums about the 10 player SNGs, so these are most often played by good players, along with 20 and 30 person SNGs to a lesser extent. However, I think that at sites like Pacific, it's worth looking into shorthanded SNGs. You have more time to make decisions, and the players are often "action" players who are playing shorthanded simply because full tables are too slow for their tastes. You can eat these guys up.
However, Party 10 person $10+1 NLHE SNGs are a safe bet. They are beatable for 45% ROI, meaning that after you play 1000 of these SNGs I believe you have the possibility of having $5000 of net earnings (45% of 11,000 is about 5000) if you are an excellent and experienced player. A realistic target for your first 100 SNGs is to try to earn $300. This is always going to be a great place for a beginner to start.
In case you are just starting right now and there are no strategy posts for you to look at, remember to play TIGHTER than you would in a ring game until it gets down to 5 players. At that point, steal blinds as necessary to survive. When it gets down to 3 players, become very agressive and don't worry about whether you finish 2nd or 3rd -- play for the win.