Patents are something that many companies should consider but probably few actually should pursue. Patents have a large profile lately with the purchase of Motorola Mobility by Google for billions largely based on the strength and quantity of patents. Google and Apple are preparing for a war over mobile devices and both camps have been "arming for battle".
Well obviously you're not Google and you don't have Google's financial resources. Only pursue patents if you have specific business objectives for them. Typically you want to pursue a patent to protect a truely original and valuable invention or process (and you need to be realistic on that point) or you believe it will increase the overall value and valuation of your company.
For tech startup companies patents may be a differeniator for investors. You have a great something new brewing and "you are protecting it" with your patents. This might help you raise some investment capital but patents will only be one of many "check boxes" your investors will be looking for as criteria to invest. Will it be a key difference to get them to invest? Probably not.
Patent attorneys will be a little biased so be careful if you consult with one. They make their money off you filing patents. That creates a bit of bias. Also be careful of the primrose path. Often patent attorneys will say you can start by filing a provisional patent and wait a full year before you file the full patent. That is correct you can but a provisional patent has little to no value. It kind of gets you going with an earlier date for your filings while you figure out what you're going to do. The price will be a couple thousand on the provisional and then when you file the actual patents the "meter really starts spinning". Overall if you pursue a full patent its going to take a couple of years to work through the process. Depending on how differentiated and how well your patent application is will dictate if and to what extent the patent office will challenge your filing. The more challenges and the more issues, you guessed it, the longer and more expensive the process will get. You should expect to pay a minimum of over $10,000 per patent by the time you'll all done and it can be much larger.
Often when you speak to a patent attorney they will want to break your idea into many smaller patent claims. Be careful on this. The pros to doing it is that if one application is rejected then you have others that might be approved but if each patent is such a small piece the overall portfolio the ones that are approved may be watered down and of little real value.
Also, remember that even if you are issued a patent it is only protection if you are willing to sue a competitor. A patent suit is going to run you a minimum of $250,000. Yes its that expensive, and a common defense from a competitor would be for them to counter sue you for violating their patents. So double your expenses if that happens.
Overall patents should not be pursued unless you have a specific and strong reason to pursue them and ultimately it would be good for you to use your network to speak to some business managers (not attorneys) that have been through the process.