I think by 10 precepts of monk he means (as i have written it, not the exact wording)..
1. abstain from killing
2. abstain from thievery
3. abstain from engaging in sexual activities
4. abstain from lying and corrosive speech
5. abstain from intoxicants
6. abstain from eating after midday
7. abstain from entertainment
8. abstain from cosmetics and perfumes
9. abstain from lying on a high or luxurious bed
10. not to accept money
The most fundamental point of these precepts as I see it is to safeguard one from bad behavior which will cause remorse. Thus the point of these precepts is to be without remorse. For the advantages of being without remorse there is this sutta: http://www.accesstoinsight.org/tipitaka/an/an11/an11.002.than.html
The benefits of not killing could be that one is harmless and feels harmless.
The benefits of not stealing might be that one has less worry over his own possessions.
The benefits of not engaging in sexual activities might be that one has more peace with reality instead of letting a mind filled with lust lead him on to focussing on fantasies only to find they are empty and worthless and also not generating the anxiety of sexual lust.
The benefits of abstaining from lying and bad speech might be that one need not worry about being "found out" and also is more harmonious with others and gentler.
The benefits of abstaining from intoxicants could be that one sets one's ambitions upon more long term things instead of very temporary states, and also one doesn't have the potentially harmful effects of confusions of these states.
The benefits of abstaining from eating after midday are that one is not so encumbered and the sensual mind states generated by eating (for one who is still in the training) don't come after midday, at least not because of eating.
The benefits of abstaining from entertainment is that one is with (long term) reality instead of temporary chatter or motion (or whatever it is they are doing in the entertainment) of entertainment. One's mind is less caught up.
The benefits of abstaining from cosmetics and perfumes is that it's a vain practice I think and how can you try to be enlightened if you are vain?
The benefits of not abstaining from indulging in sleep and sleep habits is that one is more prone to wakefulness and effort not just wordly "comfort" (feeling).
The benefits of not accepting money: I think the Buddha said this is entirely improper for a renunciant. Anyway yes they are giving up wordly ways... Money what for?
So that's my brief take on each one.
For the original poster, Talland,
These qualities help to develop freedom from remorse, a sense of ease, with ones surroundings, and a gentler inwards mind, and also the effort and motivation and sense of importance about the life of renunciation and getting out of this horrible mess (samsara).
How could one strive for enlightenment with a mind full of worry and remorse, all distraught? How could one strive for enlightenment, overcoming all sorrows, if they are still indulging in their bed?
I know if I indulge in worldly comfort (and I mean indulge, not just feeling it, but holding on to it and doing things for comfort alone), however much I indulge... eventually you have to pull yourself out of exactly that much indulgence... might take a short time, might take a while... Try to imagine an enlightened being in bed, saying, "Oh, no, I have to get up now... It's so comfortable though..." I don't think that's possible. The budda wouldn't have had any trouble, do you think? Those with deep knowledge view their own bodies like a gross carcass...
So, how did the Buddha do it? From what it sounds like, he practiced a whole lot, set his mind on development and looked into intention, was very sincere, visited teachers, and discarded everything he wasn't looking for. It is hard to "discard" things if one's mind is wrought with anger. That is why it is good to live a life without anger, full of kindness [and dispassion] no matter where one is. Otherwise, when it comes time to discard things, one might feel more pressures.
This is my take for now.