What wireless router do I need for my dell inspiron 1750? How do I know which to buy?

The E1000 is an entry level wireless N router with a 100Mb switch. This router runs 802.11n in the 2.4GHz frequency (~130Mbs) to be backward compatible with 802.11b/g. The downside is that if you have a mixed wireless client environment at home (Wii/Blackberry) - 802.11b/g, newer laptop with 802.11n) you will only ever get a max of 802.11g speeds. If you have any 802.11b only clients, your performance could be much less. If you have a mixed environment and really think you need 802.11n speeds then you should be looking at the E3000. This device has two separate radios (2.4GHz and 5GHz). You would then dedicate the 5GHz to your 802.11n and use the 2.4GHz for 802.11b/g connections. You also get a gigabit capable switch vs. 100Mb). Running 802.11n in the 2.4GHz frequency in theory is 130Mb/s and in the 5GHz frequency that is pushed to 300Mb/s. Keep in mind, that you will never get the advertised speeds, not even on b/g as the wireless protocol has a very large overhead. You are lucky if you actually see half of that speed. The 2.4GHz frequency does travel farther than 5GHz but with speed tradeoffs. 2.4GHz is also more susceptible to interference from the microwave, baby monitor, or anything else that runs in the 2.4GHz frequency.