Additional memory will speed up your computer dramatically. Assuming you are running Windows XP, 256mb RAM is about the minimum you can have without crashing your machine. I'd recommend a 512mb RAM upgrade for a total of 768mb. You can find 512mb sticks of RAM fairly cheap online (less than $40)... In fact, I recently purchased a new 512mb stick from newegg.com and am totally satisfied.

Make sure you get the right kind of memory. If you have a PC that was made by a major manufacturer, like Dell, Gateway, Compaq, etc. you should be able to google the model to find out what kind of RAM it takes. You can always talk to the people at stores like Best Buy about your computer and they can look up what kind of RAM you need for you, but for older memory models (PC2100 or less, which is likely what your machine supports), they charge a lot more than you can find online.

Installing memory is one of the easiest things to do, so paying somebody to do it is not a good idea. It literally consists of plugging it into the motherboard and snapping it in place.

MisterW