Unless you go into the mountains, it is unlikely that you will see snow.
On a cold night it may well be below freezing, during the day it will be up to about 10 degrees, which will still feel very cold to you.
Best bring layers.
For trousers, jeans or alike with underneath an extra layer or two.
A friend advices people from your part of the world to bring silk pajamas, you can wear up to five of them before it shows, she claims.
If you do not go for silk, still bring something you can wear under your jeans, leggings, thin training trousers, sports thights, maybe even long underwear if you can get it.
Same layer principle for your top half, T-shirt, shirt with long sleeves, sweater and a fleece jacket, and over all of it, a rain and wind proof jacket. If you can not get a fleece jacket at home, shop as soon as you arrive, Czech republic will have some for sale that time of the year, or invest in a winter coat. Be careful about the prices, a decent wintercoat can cost you as much as a week in the country.
If you have mountain boots, bring them, otherwise, bring the shoes which are pretty good waterproof.
And bring plenty socks. (If you get wet feet in the cold, change your socks and you will feel a bit less cold.)
If you want to experience snow, ask when in Czech republic where to go to find it, it might even be that you will have to leave the country, as the mountains in Czech republic are not the highest.
Prague is well known, but much more in Czech republic is worth visiting.
If you have never been in an European county, you should also visit a village or maybe an open air museum.
I have used the Lonely Planet Czech and Slovak republics edition, but due to other plans did not have much time in Czech republic.
I do approve of the guide though.
But there are other guidebooks too.
About food?
I think you should just walk past the restaurants, reading the menus, till you find one that attract you. I liked the traditional Czech cuisine, but there is a wider choice. All main cuisines in Europe are to be found in Prague, the smaller towns will have some choice but maybe not as much.
Many places, specially in the bigger towns, have a menu in English, but if you can, bring a language guide with a list of popular foods, as not all places can help you in English.
Czech republic is a fairly safe country, but as a tourist you need always to be aware of possible dangers.
There is a real risk of pick pockets, as everywhere in the world, so keep your passport, a credit or bank card, your tickets and some money in a pouch under your clothes, I think the kind that fits like a belt in the top of your jeans is the best.
And for the rest, behave as you would in a big town near home:
If you do not trust a person or a place, go an other way.
Do not go into the park or the small alleys at night.
Do not go home with people/men you have just met.
And if you like drinking, do not get drunk unless you know you can trust the people you are with.
(If you want to ask more, I have my e-mail option open.)
