A free lesson in "Heraldry for Genealogists" can be found at: http://www.rootsweb.com/~rwguide/lesson19.htm .

In many cases a coronet (crown) is used as a symbol of nobiliary rank. The coronets are different for nobles of various ranks, so coronets for a prince and a baron would look different. The presence of a coronet on a coat of arms of a forefather is by no means absolute proof of nobility, but it would be safe to say it is such a strong indicator that further research is motivated.

Also use of supporters (figures either side of shield appearing to support it) is a strong (but not definitive) indicator of nobility. In some countries nobles above a certain rank were required (or at least expected) to add supporters to their arms.

The number of helmets used can be another indicator. In some countries it was common for a nobleman to use 1 helmet, a baron 2 and a count 3 helmets. But variations are many and again presence of one or more helmets on a coat of arms of a forefather is not definitive proof of nobility.

Mantling (a flowing drapery attached to helmet) is often (but not always) a heraldic symbol of high nobility.

When researching your family history it is most helpful if you can identify family arms which have been quartered or incorporated with your own arms and also identify family arms where your own arms can be found as quartered or incorporated.

Part of this work may be done through Internet, using various specialized sites with advanced search facilities.

Many noble surnames include words such as "gold-" or "golden", "silver-", "sword" or symbols which are used on family's coat of arms. Among your ancestors you may also find names constructed from animals ("Wolf", "Lion") etc. Noble surnames often, but not always, seem unusual and different (which of course was a way to make it stand out).

An incholate is typically geographical predicate attached to a noble family. E.g. for Prince of Wales, "Wales" is incholate. Incholates in another sense can be used by Church dignitaries, e.g. "Titular Bishop of X Y ". In many cases incholate was family's domains, but later developed into a titular attribute. In some families loss of geographical domain caused them to write nobiliary title between their first name and surname - hence it was no longer "Count X Y", but "X Count Y", as family name became new incholate. Any incholate found among your ancestors should be carefully examined.