I'm wondering? I was wondering?

I'm wondering if you will lend me a fiver.

I was wondering if you would lend me a fiver.

Both are good - the first is present tense and would indicate that it's more a spur of the moment question. The second is past tense and indicates that you've been thinking about it for a while. Pick which is the most appropriate for the impression you want to give. If it's something big - pick the second. If it's something more trivial, pick the first.

Best regards,
Robert.

It depends if you were wondering it in the past, or you still are, but im gunna go with
Hey _____(friends name here) i was wondering if you can watch my dog on saturday, or what ever you whant to ask.

"im wondering" so that it is present rather than past with "was".

For those of us who know, it is an honor to help someone.
If you do not allow them that honor by not asking for help, you are doing them a dishonor.
Please ask any way you know how.