Ultimately, the answer will depend on your preferences, your bankroll and what you're comfortable with. There's no type of game that's "better" than any other (even if Doyle Brunson calls No Limit Hold'em the "cadillac of poker"), but I will encourage you to try them all, and for somewhat extended periods of time. All of them have their own primary skillsets (the patience of full ring limit, the aggression of shorthanded no-limit, the importance of your stack from tournaments, etc.) and playing different styles of poker will make you sharper and give you invaluable experience.
That said, my recommendations, if you're actually just starting out, are:
The reasons for starting out playing full limit tables are several, and I've touched on them in the Limit and Full vs. Shorthanded chapters. There are many skills an expert player must learn to master, and although their relative importance is not definitive (arguments for which is the most important skill in poker can and do take place all the time), my opinion is that in the early stages of your poker career, you should focus on the following three things:
You must learn how to wait for good hands. Most of the cards you are dealt are hands that will cost you money in the long run if you continue with them, and you need to acquire the discipline to toss them away, again and again and again. Folding should be your most common action in poker by far, and you need to practise it, starting now. There is no better place to do this than at a full table.
You should also learn how your position factors in when you choose which cards to play. The largest mistake beginners make is to play way too loosely, the second largest is to not factor in position in poker in the decision-making process.
First of all, understanding the concept of pot odds (and implied odds) is vital, but you also need to learn how to correctly calculate what those odds are at any given situation. This takes quite a bit of practise. Read our poker odds for dummies article to learn more.
A full table requires more patience than a short-handed one, so for that reason, playing 9- or 10-handed is preferable for picking up that skill. Position also has greater importance when there are more positions to be had, so to speak, so again full tables are preferable. Odds are, of course, necessary to calculate at all tables, stakes and forms (limit or no-limit), but they are easier to grasp when you play limit; your opponent can't suddenly go all-in on you, so you don't need to factor that in to your decision at this time.
If you don't want to play full ring limit, or you have and now want to move on, where to? To be honest, at this point it's entirely up to you. I recommend full ring limit because I feel it's the best place to learn three of the most important skills you will need as a poker player, but once you've gotten the hang of those, it's a matter of preference. Experiment - within your bankroll's limitations - with different forms of games, and find out what suits you. Read books and articles that deal with the specific type of game that you want to play, if you want to be better prepared.
But also don't lock yourself to one specific form of poker. There are great lessons to be learned by varying your game; by playing short-handed, by playing no-limit, by playing tournaments, etc. All of the lessons aren't immediately applicable to any other form of poker, but they will undoubtedly strengthen you as an all-around player. With the sizes of the online poker rooms, there are always games available for almost every form of poker that there is. Take advantage of that!