I will start with this as it is one of the most asked questions.
When trying to decide on a camera the most important thing is setting a budget. It is very easy to get carried away when you look at all the toys available.
All the major camera brands have a different lens mount and lenses you buy today should be regarded as a long term investment. In time you will probably trade up your camera body, whereas your lenses will be with you for longer. With lenses you do generally get what you pay for. So a budget lens will not compete with a mid priced or top end lens. The question here is should you save up for a little longer in order to get a better quality lens that will keep you happy for years.
The best advice I can give is having set a budget look at web sites like Warehouse Express ( UK ) to see what you may be actually be able to get for that budget.
Draw up a shortlist of possibles then look at an unbiased review. Sites like DP Review are good with very thorough reviews.
http://www.dpreview.com/
When it comes to the camera itself the only advice is to actually try and handle what you think you might buy first. Is it compfortable to hold - too large or a bit small. Look through the viewfinder - be happy with the view and the way information is displayed. Look at the body - how easy it is to press the control buttons and generally operate the controls. Also consider the range of accessories available - remote release, flash etc.
In the end the best camera is the one
YOU LIKE and
NOT what Joe Bloggs or a salesman says, so never get badgered into a particular buy. Remember a lot of camera users will, if asked the question, rate their kit the highest and what is right for them may not be right or affordable for you. By all means ask for user comments as it may help.
Don