You should set aside about 30% of these income to invest.
Depending on how much risk you wanna take, you can invest in penny
stocks(short-term) or blue chips(usually long-term). Also, do not
only invest in one sector. You should diverge and invest in a
basket of stocks from the different sectors to minimise risk.
However, if you are not so much of a risk-taker, you might think
about investing in bonds or unit trusts, which may take a longer
period before you see your gains but is much steadier, meaning even
if you lost, it wouldn't be as heavy a penalty to pay as if you
invest aggressively.
There are also various insurance policies that are useful to
investors. You might want to check them out. Or you may want to
seek a financial advisor for advice for saving, investing, and
insurance. 
