Assuming you have understanding of the share market and time to track.
Put Rs. 3Lakh in an FD account. Choose any share of Banking Sector or PSU with a PE below 5to 8 or below 10 and F&O lot size around 5000. Buy one lot say UCO Bank at X price say 51.50 book a sale immediately at 52.20. Some times market moves opposite buy one more lot near X minus 5%, Hold if price are still not favourable and sell when price comes back 2 days or 20 days.

experience is that you shall get atleast 30% RETURN. DO NOT PANIC. Do trade with the broker who gives atleast 2 days time to top-up margins.

1. Keep 30% of that deposit in bank. If you need in case of emergency.

2. Start investing in mutual funds at regular intervals. Don't invest all of that money 3.5 lakh in stocks or funds in a single day.

3. Get investment education. Keep track of market , bust most important is keep track of economy. Stocks markets looks at future .A common man knows about economy much earlier than executives. If you see that business is slow in your shop or there are less customers to a retail shop you go to. It's time for you to be concerned.

4. Invest 5% of that money ( 70%) each month into 3 stocks. If possible. For example buy 50 cipla, 50 castrol and 50 tv today this month. Buy next month same stocks .

Idea is that you don't want to get caught into a market tragedy. Rule #1 of investing is to protect your investment.

5. The biggest challenge a common investor faces is , when to sell a stock. and to be frank there is no easy answer to that. If you bought a stock at Rs 100 , it gets to 200, should you sell or keep ?

The real reason stocks are supposed to go up is because investors think that this company or business has more value. If the stocks doesn't go up than some company out there will acquire the business.

Look at what happened in case of uttam galva steel. Stock traded at 23 Rs a year go. Now Mittal is bidding for this company at 122.