Get an N router if in the future you think you'll buy an N laptop.
If your laptop is wireless G and you buy a wireless N it won't have any features the N has (i.e. distance, speeds). It will be connected through G, and G only.
So my suggestion is that you stick with a G unless you are planning on purchasing an N laptop in the near future.
The question I have is, is it worth upgrading to a N rated router like the Linksys WRT310N Wireless-N Gigabit Router if the primary wireless component that I am running is a Dell Inspiron 1525 laptop which I believe has a 802.11g Wireless card in it. The only other items running off the router is the standard wired desktop and an Epson Workforce 600 printer which I have running wirelessly.
The only other factors that may be needed for the answer is that the laptop will usually be running within 30-50 feet of the router (very rarely at a distance of 80-90 feet), the printer is in the same room (about 8-10 feet away), and the cable that I am running is through Comcast. I have their Triple Play offer, and according their website it says it is running at "Download speeds up to 16 Mbps with PowerBoost