Catalog For Worldwide Stamps

I just bought a very old album (1950 issue) with LOTS
of old stamps, some of which seem to be the very early issues. They
were of some of the first pictured anyway. There are MANY
countries with lots of stamps.
Where can I find a list of Worldwide stamp values?
Any help would be appreciated.

The most common worldwide catalogs would be Scott, Stanley Gibbons, Miohel... (not necessarily in that order).

In the US, check your public library for the Scott stamp catalogs (sometimes they are in the reference section, not the circulation section).

There are some free online catalogs, but since they are usually sales sites, they usually are not comprehensive (covering mostly recent issues of past 50 years) and are not useful if you don't already know the basics of IDing stamps.

Put the album under your arm,
pop along to a stamp dealer, and politely
enquire if he/she can give you an estimation.

They can browse and pick up any that may be of value,
most will be worth 20c