The find feature in QuickBooks should definitely be on your icon bar as a shortcut. I use this function frequently and it saves a lot of time. To use the find feature you can go to Edit/Find, hit Ctrl+F or add it to your icon bar by right clicking on the icon bar and customizing it.
The simple search allows you to look for transactions based on the type of transaction (bill, invoice, check etc). After you have selected the transaction type you can then search by amount, date range, number etc. This is really useful when you have some of the information for a particular transaction but not all.
The advanced search is where you can really drill in on things. It gets a little detailed on the advanced tab. However, by playing around with the function a little you will find it a pretty useful tool in finding transactions quickly. I use the amount search more often than any other advanced filter. For example if you come across an electronic withdrawal on the bank account and you are not sure if you have accounted for it in QuickBooks the Find/By exact amount function may prove handy. If the transaction is for a very specific amount, $185.23 for example, it is typically faster to search by exact amount rather than any other method. Many times with debit or credit card purchases the payee is missing or unclear. Using some function of the find feature depending on the information you do have may be the fastest way to figure out what the charge is without having to ask the boss.
The find transactions function can be useful to QuickBooks users in many different ways. With a little experience using the function you will learn how it works best for you.