If there's one thing I have too many of (besides shoes), it's lamps. I LOVE them. They provide soft light in areas for reading, come in tons of designs, and can be a very affordable accessory in your home. You can find small ones for your bathroom and larger ones for your kitchen. At night, they can provide light for you becoming a make shift night light.
A great place to find inexpensive lamps is at IKEA. You can pick the base and lampshade separately, creating a one of a kind design. Target also has nice tabletop lamps that can jazz up any room. I like modern designs so I like to pair up Lucite (transparent plastic) lamp bases with patterned shades or even a simple white or cream color shade. I also love lamps that have a built in dimmer or can handle a 3-way light bulb. This allows you enough light for reading/studying or to create an atmosphere that is more relaxed and cozy.
I also like integrated lighting. Integrated lighting is defined as combining elements (lights & bookcase in this example) so as to provide a harmonious, interrelated whole. So for example you can light up a bookcase with spotlights or clamped lights that you attach to the top or inside of the case. This is integrated lighting. I have two lights clamped on the top of my bookcase. This is really nice for lighting up photographs or vases. Another great thing about these lights is that you can move them around. They are not bolted in so you can change the location as well as what you are lighting up. They also swivel 360 degrees so you can also use them to light up a wall behind the bookcase. A great place to find integrated lighting is IKEA.
Lighting your office can be a challenge but I find the sleeker, the better. I like modern lamps for my office. I like a streamlined look. I have the Antifoni work lamp from IKEA in silver on my desk and it's great. The adjustable arm makes it easy to direct the light and the overall design is sleek yet simple. The silver color also stands out against most colored office desks. I have a black desk with silver legs and they coordinate well together.