Questions on Castling

Like every other beginning chess player, I've heard the basic drill: "Castle early, castle often." Most of the time I do this, usually on the kingside. Sometimes, though, the "game analysis" suggests I should have continued with other developing moves on the queenside first, so my first question involves timing. 

Is it best to develop on both sides before castling? 

My next question is somewhat general. I've heard that castling on the kingside is more secure because the king is farther from the center of the board.  But are there times when it would be better to castle queenside? Are there any advantages to it? Basically, my question is this:

How do I decide which side is best for castling?

My third question arises because of my inexperience. Time after time, I've patted myself on the back for castling, only to end up with my king trapped behind his own blockade of pawns. Sometimes I try to move a pawn early on to provide an "escape route", but doesn't that also allow an opening for my opponent? So, my third question:

What is the best way to protect my king in "the castle" without getting him trapped?

I'm sure my questions sound simplistic to more experienced players, and maybe I'll figure out the answers myself as I play more games. But could someone maybe give me some general advice... in beginner's terms? 

I'll be grateful for any assistance here. I'm fascinated by this game, and I'm trying to learn all that I can. I've just got to go slow and get the basics down first. 

Thanks! 

It entirely depends on the opening. Sometimes White will castle after a mere four moves, e.g. in a Réti set-up after Nf3, g3, Bg2 castling kingside (‘short’) is already possible on the following move.

In other cases - especially against Sicilian set-ups, when White wants to castle queenside (‘long’) - this can take up to nine moves or more. In rare cases White’s even doesn’t castle at all.

As far as Black is concerned, he/she will often follow suit. In the first-mentioned Réti set-up, if Black has copied White’s moves, (s)he may safely castle short as well.

But in some Sicilians it may be wise to wait till White has made a decision whether to castle short or long.

These are very general rules.

Practice will teach you what to do.

Again, in the Sicilian openings (or the Pirc/Modern Defence) with opposite castling, you may get a mutual race between White attacking Black’s king on the kingside and Black doing likewise on the queenside with White’s king.

Articles by Grandmaster Gserper:

https://www.chess.com/article/view/to-castle-or-not-to-castle-chess

https://www.chess.com/article/view/kingside-castling-or-queenside-castling

Generally in the opening. Within the first 10 to 15 moves you want your minor pieces developed, have control or at least be fighting for control of the center four squares and have your king castled.

That being said, the position always dictates your actions.

I often play the London System which often leads to positions where there is a pawn wedge in the center that is blocked by opposing pawns.

Most of the action will be on the wings so your king is safer in the center behind all the pawns.

Once I played a game where my opponent traded every piece as soon as it was developed so by move 15 we were in the endgame.

In the endgame your king needs to be active so castling in that game was inadvisable.

I would say that in 90% of your games, you want to castle early.

 Generally you want to castle and connect your Rooks within the first 5–10 moves.

@1

"Is it best to develop on both sides before castling?"
++ No. Castle early and often. Castling is a developing move. In connects the rooks and thus activates the rooks, the most powerful pieces after the queen. It also brings your king to safety.

"I've heard that castling on the kingside is more secure because the king is farther from the center of the board.  But are there times when it would be better to castle queenside?"
++ Yes, there are times when O-O-O is better than O-O. Examples are when your opponent has played ...g6 and you want to attack h2-h4-h5 supported by Rh1 or when your opponent has played ...h6 and you want to attack g2-g4-g5 supported bt Rg1.

"How do I decide which side is best for castling?"
++ Generally O-O, unless you want to attack h4-h5 or g4-g5, or O-O would not be safe.

"What is the best way to protect my king in "the castle" without getting him trapped?"
++ A good defender of O-O is Nf3, or sometimes Nf1.

Ideally, your castling shouldn't be decided on the fly but instead be an integral part of the opening decision.

For example, playing the Queen's Gambit as white, I castle kingside unless my opponent takes my bishop that I've retreated to g3, opening up my h file. Then I'll castle queenside because the rook on the h file is much stronger.

Moving all your knights and bishops out and then castling is usually fine. As with every move, you need to make sure your pawns and pieces are sufficiently defended before castling.

When you see your opponent making threats around your castled king, I think it's best to consider defending with pieces before considering pawn moves. Any pawn you advance in front of your king can turn into a permanent target.

Kingside gives you weak pawns and not much protection. Queenside is safer and develops alot better.

At your current level, you will progress quickly by simply developing your kingside quickly, castling, and controlling the center (all assuming there are no tactics to deal with at the time).  Later you will realize there are exceptions to this, and even sometimes you do not want to castle at all, but those are exceptional cases that you do not need to focus on right now.

Usually the best pawn to move for king's escape is the h pawn, but sometimes the g pawn is a better choice, especially if you have a bishop sitting on f3/f6.