Generate a tags file using ctags

$ ctags *.c
$ ctags -R .
$ ctags -L flist

For Linux kernel and some other packages which have built-in tags target in Makefile:

$ make tags

Configure Vim to locate a tags file

set tags=/my/dir/tags
set tags=/my/dir1/tags, /my/dir2/tags
set tags=tags;/

My ctags settings in ~/.vimrc:

"ctags settings
set tags=tags,../tags,../../tags,../../../tags,../../../../tags,../../../../../tags,../../../../../../tags

Jump to a tag

• :tag <tagname>

• position the cursor over a tag name and then press:

  Ctrl-]

• $ vim -t <tagname>

Come back from a tag jump

• :pop

• Ctrl-t

Reference

1. Tip #94: Questions & Answers about using tags with Vim.
2. Ctags Home Page.