Signing up on eBay is relatively easy, but I always caution people to think twice about choosing your User ID and password.

eBay lets you choose your own User ID, Making up a User ID can be fun—it’s a chance to make a cute name for yourself that describes what you do or who you are. But remember, if your interests change, you may regret choosing too narrow a User ID.

You can call yourself just about anything: you can be silly or creative or boring. But remember, this ID is how other eBayers will know you. So here are some common sense rules:

Don’t use a name that would embarrass your family

Don’t use a name that might make people be wary of you. If people don’t trust you, they won’t buy from you.

eBay doesn’t allow spaces in User Ids, so make sure that the ID makes sense when putting two or more words together. You can use hyphens, underscores or a dot between words—my own User ID is old.books. That already tells you that I probably deal in books

You can change your User ID (once every 30 days) if you want to, but it’s not really a good idea. You are identified by your name and if you change it often, people will think you are trying to hide something and they might have trouble finding you for more purchases.

Still, I recently changed my ID. For years my ID was my name, all in one word: raeosenbaugh. My theory when I registered that name was that there is no one else in the world with my name (lucky me!) so that ID will not already be taken. I used that ID for a long time until I realized that 1- it’s not real pronounceable if you don’t know me personally, and 2- it does not really tell what I sell.

eBay has some User ID rules to live by:

No offensive names (like *&%*#girl).

No names with eBay in them. (It makes you look like you work for eBay, and eBay doesn’t want to see that.)

No names with & or @.

No symbols such as the greater than or less than symbols (> <) or consecutive underscores ___.

No IDs that begin with an e, followed by numbers, an underscore, a dash, a period, or a dot.

No names of one letter (like K), even if that is what you’re known by.

Picking a good password is not as easy (but is just as important) as it may seem. Whoever has your password can "be you" at eBay — running auctions, bidding on auctions, and leaving dangerous feedback for others. Basically, such an impostor can ruin your eBay career — and possibly cause you serious financial troubles.

As with any online password, there are common-sense rules to protect your privacy:

Don't pick anything too easy, such as your birthday, your hubby’s first name, or your Social Security number. If it's too easy to remember, it's probably too easy someone else to figure out.

And, another common sense warning: Don't give out your password to anyone — it's like giving away the keys to the front door of your house.

And a final suggestion: change your password every few months just to be on the safe side.