Yahoo Finance - all around most useful for stock market information. You can enter multiple ticker symbols to get summary info about your stocks. Once you go to a specific stock, on the left side you will see over 20 links with info about this stock - profile, key statistics, SEC filings, technical analysis - all free. One of our favorite features is the Historical Prices - it gives you access to historical price data - and yes, you can download it to your computer in an Excel format. If you are going to do any kind of technical analysis or computer modeling - this data alone is priceless. Columnist to read: Robert Kiyosaki.

Bloomberg - this used to be a great site, until they "improved" it. Now we use it only for a quick glance at foreign markets and commodities, and an occasional check of interest rates. You can drill down for more details on each. It is also a good site to see what Wall Street is excited about today - but don't spend more than 5 minutes - tomorrow Wall Street will be excited about something different. A perfect example of (useless) information overload. Columnists to read: Michael Lewis, William Pesek, John Dorfman (with caution).

MSN Money - another site full of useful research info - we use it to look at analysts following the stock (go to the site, enter a company ticker symbol, then on the left side, under Research, click on Analyst Ratings). We do not particularly care what the analysts are saying. We just want to know how many of them are following the stock. If there are many of them ( more than 20) - then Wall Street already knows about the stock. However, if there are only a few ( less than 10) then the stock is pretty much unknown - which means if it ever gets "discovered" - the upside could be huge. Obviously it's not guaranteed, but it's a nice checkmark to put next to your potential "10 bagger".

Pre-open stock market prices - this site is available usually after 9 pm PST - it can be used to see how the stock market will open next day. If you see that the opening will be lower than today's close - and you are about to buy a stock - it may be worth a try to put in a limit price lower than you originally planned ( the flip side is that if you are right, and the stock is about to take off - it may do so despite the overall lower market - in this case, you will miss a trade, or will have to enter at a higher price than planned). We are not convinced that it has produced a net benefit in our own trading, but we still like the site.

Morningstar - mutual funds - all you can eat - we are not big fans of mutual fund investing, but if you must - this is THE site to do mutual fund research

Vanguard - mutual fund - low cost - we are not big fans of mutual fund investing, but if you are just starting or have very limited time - this company charges v.low fees, and has index funds that cover entire known universe

Pro Funds - mutual fund timing - designed for active trading - mutual fund timing used to be a very profitable strategy - until funds started to charge 1-2% fees for "frequent" trading ( holding funds for less than 60-90 days). However, both sector players and index players wanted more - so new funds were created with active traders in mind. In addition to many sector funds, they have funds that allow you to take advantage of falling markets as well. Be careful to make a distinction between mutual funds offered by ProFunds and their ETF-like funds - those trade like stocks and often have low volumes, which makes prices easy to manipulate.

Rydex Funds - mutual fund timing - designed for active trading - another fund family designed for active trading. In addition to many sector funds, they have funds that allow you to take advantage of falling markets as well. Be careful to make a distinction between mutual funds offered by Rydex and their ETF-like funds - those trade like stocks and often have low volumes, which makes prices easy to manipulate.

Realtor.com - excellent site for anybody who is interested in real estate. We particularly like the map search - simply click on the state you are interested in. Great site for doing remote research, identifying properties to investigate. Even better, by looking at the listing brokers, you can see who brings in good listings, who understands multi-unit properties, commercial properties, etc - excellent tool for building your support team in a faraway location - once you find a good broker - it's a snap to get good insurance agent, good title company, a handyman - just ask your broker and people he recommends.

Zillow real estate site - we are torn about this one - we like their satellite map, with little flags marking houses for sale and ones sold ( sold are more useful, since they indicate market prices). On the other hand, the site feels clunky, and their pricing algorithm is all over the place - on one house it can be +15%, on another in the same neighborhood -20% or +50% - that's a lot of money. Not to mention that when it comes to mobile homes, it's simply wrong - it prices them as if they were regular houses (Oct. 2007). Zillow is also limited in its geographic coverage. We use the site for nice aerial maps of the cities of interest, and to look at recent sales, and where they are clustering. We ignore everything else.

Interest rates and loans - great site if you want to find out current interest rates - home loanes, car loans, credit cards, college loans, CDs, saving accounts - it's all here.

Treasury Direct - government bonds - this is a government site about Treasury Bills, Notes, Bonds, TIPS, EE savings bonds, and I Bonds - you can learn about them, you can even buy some online. Since Treasuries, after tax, yield less than the official inflation rate, we would only consider them as a place to temporarily park our money.

ShadowStats - inflation - non-government numbers - if you ever wondered how is it possible that government reports 2-3% inflation, while the food prices are up 30-70%, gasoline has doubled, houses have doubled or tripled - this guy decided to read the fine print - how the government plays with the numbers. Most educational.