Wa Alaykum Salam wa Rahmatullahi wa Barakatuh,
In Arab culture, a Shaykh is any man over age of 40. In the Islamic sense, a Shaykh is a learned Muslim scholar.
Unfortunately there is a great deal of ignorance and misconceptions about who exactly is a Shaykh. - There are many "celebrities" who come on the various Islamic Satellite TV channels, on Youtube and websites and who either openly use the label Shaykh or let others call them that, whereas in reality they may not even be students of knowledge and may spread incorrect ideas or have weak understanding of the Deen.
Ibn Mas'ûd - Radiallâhu 'anhu - said: "You are in a time whose Scholars are many and its speakers are few. After you will come a time whose Scholars are few and its speakers are many." [related by at-Tabaranî in al-Kabîr (8066) and al-Bukhârî in Adab al-Mufrad (789) and declared to be Sahîh (authentic) by al-Hâfidh Ibn Hajr in Fath al-Bârî (10/510) ]
Also from The Piece of Advise 'Ali Radiallâhu 'anhu gave to Kumail ibn Ziyâd
"The people are of three classes:
The righteous Scholar, the student of Knowledge being upon the path of salvation and the confused rabble who follow everyone who calls out - bending along with every wind - they are not enlightened by the light of Knowledge, nor do they lean upon a firm support." [Part of a lengthy piece of advice - as is reported by Abû Nu'aym al-Asbahânî in Hilyatul-Awliyâ (1/79-80).]
The ascribing of titles is dangerous because those who really deserve them, who really are oceans of knowledge and wisdom have their words and explanations compared and contrasted with those people who are not scholars. The people of knowledge are not of equal levels, some have much more knowledge than others. Some have permission to teach and give fatawa, whilst others do not.
This does not mean you should not respect your Imam or any person explaining Islam. But, to be careful and know who you are taking your knowledge from.
Here are some previous threads which I hope will help you to learn more about who we should take our knowledge of the Deen from.
Why Manhaj? (methodology) By Shaykh Saalih bin Fawzaan al-Fawzaan
http://www.turntoislam.com/forum/showthread.php?t=25431
"The Scholars are those who have sat and studied with ulema of Ahlus-Sunnah for many years. They are those who derive their Islam from the clearest of sources and who are known by the scholars and given permission to teach from them. Even, a person can not claim to be student of a Shaykh unless he is actually said by the Shaykh to be his student. We have unfortunately, some people especially in the west who make these claims, but in reality, their manhaj is not same as those they claim to be students of and certainly, are far from that which came from prrevious generations of Muslims."
Becoming a Scholar
http://www.turntoislam.com/forum/showthread.php?t=6769
The Prophet said:, “The virtue of the scholar to a worshipper (Aabid) is similar to the virtue of the moon when it is full to the rest of the stars. And verily the scholars are the inheritors of the Prophets. Verily the Prophets did not leave behind dirhams and deenars, but rather they left behind knowledge. Thus whoever takes it, takes it as a bountiful share.” – Authentic, narrated by Abu Dawood, tirmidhi, and Ibn Majah.
List of some of the Scholars and Imams of Past till the Present Day
http://www.turntoislam.com/forum/showthread.php?t=25434
Alahmdulillah