That is a nice question; in fact, you should do a bit of both. Your broker will have access to a lot of information and research. Also, since the brokers are in the stock market, they get to hear a lot of market ideas. Some call it grapevine, but that is still useful to you. When you talk to your broker they can share these ideas with you. You may not directly go and execute the trade as it is but you can surely take that as an idea and build on it. Having said that, it is always better to always do your own probing before buying or selling a stock.
Actually, it is not very difficult. Most brokers will offer you company databases online which you can play around with. If your broker has given you an idea of what stock to buy, you can always do some homework. For example, find out if the company is making profits or losses. Check some basic ratios that can tell you if the stock is performing well or not. Valuations can be easily checked with P/E ratio etc. If you are familiar with using charts, also check if it's a good level to enter or exit the stock. In fact, it is advisable that you familiarize yourself with charts and technicals if you want to buy and sell shares in the market.