We are preparing a small bilingual Powerpoint show about tulips for our exhibition in Turku. I might have some questions.

The headline should be something like

                          Laleler  -  Sultanların Çiçeği

I am uncertain about the use of singular and plural here. Lale or Laleler? Is it disturbing that çiçek is singular?

What is the rule about initial letters in headlines? Is capital letter used in the beginning only or in every word of the headline?

You certainly understand it has to be perfect.

Singular of "Lale" should be used as it already refers the plural [the whole lale family] but in singular form.

and  because the agreement on numbers.  Singular ---> Singular 

                                                           Lale     ----> çiçek

So, I would say as ;

Lale  -  Sultanların çiçeği 

=====================

Yes, it should start with capital Letter. Not every word of the headline. An example from Zaman Newspaper ;

Geçmiş zamanların sureti: Lale

http://www.zaman.com.tr/pazar_gecmis-zamanlarin-sureti-lale_802128.html

Unless it is a proper name referring a proper name , then both initial letters should start with capital letter ;

Lale Devri --> Tulip Age [ this refers a special period of time during the Ottoman Times]

Sample headline ;

Lale Devri´nde aşk

http://www.zaman.com.tr/tv-rehberi_lale-devrinde-ask_1027223.html

The rule [tradition] is that, It has become a tradition that  newspapers and magazines are most of the time using capital letters in only initial letter of their headlines.

examples ;

Kamyon  eve girdi.

 Mini seçim yarın. 

Gazeteler ve dergiler oluşan geleneğe uyarak haber ve yazı başlıklarında çoklukla yalnız ilk kelimenin başında büyük harf kullanmaktadırlar: Kamyon eve girdi. Mini seçim yarın. 

The rule [tradition] is that, It has become a tradition that  newspapers and magazines are most of the time using capital letters in only initial letter of their headlines.

examples ;

Kamyon  eve girdi.

 Mini seçim yarın. 

Gazeteler ve dergiler oluşan geleneğe uyarak haber ve yazı başlıklarında çoklukla yalnız ilk kelimenin başında büyük harf kullanmaktadırlar: Kamyon eve girdi. Mini seçim yarın. 

The rule [tradition] is that, Traditionally, the  newspapers and magazines are most of the time using capital letters in only initial letter of their headlines and titles.

examples ;

Kamyon  eve girdi.

 Mini seçim yarın. 

Gazeteler ve dergiler oluşan geleneğe uyarak haber ve yazı başlıklarında çoklukla yalnız ilk kelimenin başında büyük harf kullanmaktadırlar: Kamyon eve girdi. Mini seçim yarın. 

Yardımın için teşekkür ederim tunci.

The one grammar rule which until now I have no idea whatsoever of is the border between singular and plural of abstract and hyperonyme NP´s. Fortunately the wrong choice is not a fatal mistake most of the time.

its not a grammatical rule here but a matter of expression. if you want to say "laleler" than you should say "sultanların çiçekleri" because one flower cannot define the whole of the flowers, can only define the one-of-many

OK, I give up. I have been learning Turkish for quite some time and it has been full of big struggles and small victories. I haven´t posted much, but I´ve visited this site almost everyday since I registered about 4 years ago. I struggled with making sense of grammar, then things eventually made sense. However, I feel like total and absolute failure when constantly confronted by things like "hyperonyme NP´s". I admit defeat. The simple becomes impossible. Perhaps I should spend my time attending a course in linguistics before I bother continuing with Turkish again.

Could admin please remove me from this site, thank you.

Oh please sahk dont give up. After all studying you came a long way. I wish I could help you more. But the time difference and my studies hinder me. I think you should go on.