For starters, there's the Reverb Price Guide which has thousands of entries with pictures and details on various guitars and other gear.
Some browsing around the Fender section of the Price Guide can definitely help you find which model you have.
So you need to figure out the year of production for your Fender guitar or bass. Fenders rank as the most frequently bought and sold instruments on Reverb, and finding a precise date of manufacture can be key to determining the value and specifics of an instrument.
The most important thing to keep in mind when dating a Fender is the highly modular nature of the designs.
Here is what the neck date and body date look like from a 1952 Telecaster: If you're not comfortable removing the neck of a guitar to peek at the date marker, I encourage you to take it to a local tech or luthier.