As an angel investor to startups, I'm still surprised to find entrepreneurs who expect investors to give them money, and assume no strings attached. Would you do that if it was your money? If the entrepreneur wants total control of their own venture, with no one looking over their shoulder, they should work within the limits of their own resources, a process called bootstrapping.
Angel and venture capital money always comes with ownership and management implications, starting with the obvious ones outlined in the term sheet for the deal. These normally include what percentage of the company the investor now owns, how and when tranches of money will be delivered, and even how and when you can sell your own shares (liquidation preferences).
Finally, entrepreneurs should never forget that investors really believe that they are there to help (not like "I'm from the IRS and I'm here to help"). In fact, they usually invest because they have extensive experience in your business domain, often have strong convictions on what it takes to succeed, and probably would like you to do it their way.
In any case, your startup is now part of some investor's portfolio, so you need to treat the situation like reporting to a new boss, and not like a new freedom. That means listening to investor expectations, communicating regularly and effectively, and assuming that all your efforts will now be monitored in the following ways:
If you haven't done this before the investor deal was signed, now is the time to talk to each of your peers who may have received money from the same investors. These peers can tell you what works and what doesn't work with a given investor. Also, these peers are now your competition in a portfolio ranking, so you need to know to stay ahead of them in the pack.
If your startup is one of the high fliers in the portfolio, be aware that investors may ask you to take even bigger steps into the unknown, hoping you can be the next Google. Certainly you don't have full control, but don't get talked into taking unnecessary risks just to make the investor's portfolio a leader among their peers.
In reality, when you take someone else's money, your job as an entrepreneur gets even tougher and riskier than before. I've seen many startups that might well have succeeded, if only they had not attracted all the money they wanted. In the startup world, hardship and struggles are often your best teachers. If you do take investor money, do it with your eyes open. It can disappear quickly, leaving you with just some heavy strings.