First off...I didn't mean to start an arguement with Pax and the others on his "side". Some people (mostly on my "side" seem to be getting a little hot under the collar....)
If all the players in the group are happy with the notion that once you make a choice for your character, you're stuck with it short of a wish, a quest or retiring the character then great.
I do help my players with their characters. EXTENSIVELY! I offer to help them make their choices, I give them sample spell lists with reasoning for why certain combinations of spells work, etc. If you let a rank newbie pick spells without any guidance, they will almost certainly come up with a completely useless combination of spells and abilities.
This is where my attitude on this issue really comes from. Most of the players in my group started playing around the time 3e came out (some before, some after). We play about every 4 weeks or so. Sometimes there are longer breaks when every one is busy...so let's think...3e came out around August in 2000, right? So since then we've played maybe 20 times or so. What does that mean? Most of the players in my group ARE rank newbies (no offense to them if they are reading this...they do well, but often need a good bit of guidance, which I truely enjoy giving).
The other experienced gamer in this group is also the other DM. He recently finished up a campaign that lasted through 7th level or so. He didn't give as much guidance on character creation and level advancement as I usually give and some of the PCs just sort of stopped being (or never were) very effective. Around 5th level it got really bad and I suggested that he and I each sit down with some of the players and help them "rework" their characters. This was a complete overhaul...spells, skills, feats, even moved around some ability scores.
Interestingly enough, I helped our bard and one of the bits of advice I gave her was to generate her spell list as if she was high level ( I suggested 12th...20th is way way too far in the future, IMO) and pick her future spells from that list. That's also what I did when I played a Rogue/Sorcerer.
Now...would I be more "strict" with more experienced players? Maybe. But at the same time, even experienced players can make mistakes or could make choices based on invalid assumptions and that could lead him to be unhappy with his character. For instance...you can find any number of long threads on this board about certain vague (and many not so vague) rules. He may assume I would see a rule one way when really I see it another thus rendering one of his choices to be not as useful as he had hoped. In cases like that I want him to be able to make a change. I want to rule consistantly between all players, so I've just let it be known that I'm flexible in this area and if a player is unhappy with his character, he can make small changes over time and can even ask for assistance in that endeavor.
Another reason I do this is that since we play so rarely, it is difficult for us to experiment with all sorts of class, feat, spell and skill combos. So I want people who want to try something a little different to see if it will be fun to be able to do so without completely retirin their character.