how much risk%%%

i am new to hc and this is my first post. i have had a go at investing in share market with $100k since may this yr. what % of this amt would anyone invst in one stock and can you be too diversified. is it better to have more invested in less stocks? say 10 with 10% in each. and what % should i aim for if i want to try day trading. i seem to get impatient and sell out too soon, just to see the stock price go up. has happened too many times. i keep changing my trading plan (if you could call it that) what are other people's trading plans? have been reading threads on hc for last couple of weeks and it is more addictive than facebook!!!!