Where should i invest my money with good interest?

The safest investment is cd or regular savings account.The disadvantage of cd's is that they require you to leave your money alone for the term of the cd,or you lose your interest.Now they have some attractive online savings accounts that pay interest that is equal or better than a cd and you can access your money anytime with no penalty.Two the best are www.hsbc.com and www.etrade.com. I believe they both currently offer 5.05%.
If you are young,you might also consider some of the mutual funds,such as www.vanguard.com,These are longterm investments that over time have historically paid off at a higher rate than cd's.They are linked to the stock market and thus are prone to fluctuations in value.If your goal is to save for retirement then a Roth IRA is your best bet.These are tax free until you withdraw the funds after you retire and are in a lower tax bracket.Hope that all helps.

Without knowing your time horizons, risk tolerances, age, etc... there is no way to answer this question legitimately.

if you have the money, but don't know to invest, i think you must invest in education first.

u have to spell out
a)spend time
b)spend money
c)how much money u would invest
d)your age,your need of funds at different times of your life etc
e)what is your qualification,job experience,male/female etc
then one can say few words

What percentage is "good interest" to you?

Some considers 4% a year as good if they can have it and the principal back. 25% a month is too bad, - very, very, very bad - if the principal and interest both disappeared!