I need information about effective concentration of HPLC buffers: Pyrrolidine, TEA, 1-methylpiperidine, glycine, TRIS and ammonia. Thank you.

I do not understand the question. You get better buffers at higher concentrations, but you are often limited by the solubility of the buffer. On the other hand, for LC/MS applications, buffers as low as 20 or 10 mM are used. In addition, for MS applications you need to use a volatile counterion, such as formate or acetate. For MS application in the alkaline pH we typically use ammonium bicarbonate.
I hope that this random information helped. Otherwise, please explain your question better!

Dear Mr. Neue,
When we use phosphate as buffer, we need to make the buffer in concentration of 25 - 50 mM. Is this range of concentration commonly used with other type of buffers? Or are there different rules for those buffers (Pyrrolidine, etc.)?

In principle, you want to use the highest buffer concentration that you can get away with without running into buffer solubility problems. For normal RPLC, the concentrations of 25 to 50 mM are usually fine. You can manipulate the solubility to some extent with a different choice of the counterion, if needed.
I have not used methylpiperidine, but the others are all unproblematic in this concentration range for most reversed-phase applications.

You mean buffer capacity ? Look at The Buffer Wizard TM - A Free Automated Buffer Preparation Calculator : http://www.zirchrom.com/