First off, the easiest and least expensive thing to do is to run "msconfg" from the "Windows 7" menu (type msconfig at the bottom, and it will ask you for your admin password and then the window will come up). Go and look at the "Startup" tab and unclick anything that you don't need. Anything that has a check mark will be starting up while you boot, so they will "slow down" your boot. You can google startup items that you don't know about to see if they're needed at boot time. There may be a lot of stuff there that doesn't need to run at boot time. So, by using this judiciously, you can speed up your boot time.
The best thing to do that will also cost you some money is to replace your main hard disk with an SSD. This will radically cut your boot time, but it does cost some. Although the price of fast 128GB SSD's has come down. You can have a smaller SSD for C: drive, and a larger hard disk (maybe your old C: drive *smile*) as a secondary data drive, and this will really speed things up. It is fairly easy to do this using software like "Paragon Migrate OS to SSD".
There are other things you can do as well, such as making sure that your C: drive is defragmented, that you have removed all the software that you don't use, and that you use a good, lightweight virus scanner rather than some of the very heavyweight ones that are around that more system performance away than they contribute in terms of security.
But the first two above (msconfig "startup" and getting an SSD) will generally give you the most bang for the buck *smile* in getting your boot time under control.