About vav as a consonant: When the vav is at the beginning of a word, it will make a /v/ sound - ורד (rose) is pronounced /vered/. וילון (curtain/drape) is pronounced /vee-lon/. It is also likely to make a /v/ sound when put in the end of a word - סתיו (fall season) is pronounced /stav/. יחדיו (a beautiful word for "together") is pronounced /yakhdav/. Now let's talk about vav as a consonant in the middle of a word. If there is only one vav in the middle of a word - it is probably a vowel. If there are two vavs in the midlle of a word - then it's a /v/ sound. For example - ברווז (duck) is pronounced /barvaz/ - the two vavs stand for the /v/. תקווה (hope) is pronounced /tikva/ - the two vavs stand for the /v/.
Unfortunatly, hebrew doesn't have "real" vowels to guide you while reading. However, there are letters that may, sometimes, be "vowels" - like the letter ו (vav). A vav in the middle of a word may indicate an /o/ or /u/ sound. For instance - גורם (noun - cause, verb - cause/s) is pronounced /gorem/ - the Vav stands for the O. Hanukkah is חנוכה - the Vav stands for the U. The letter י (Yud/Yod) in a middle of a word may indicate an /ee/ sound. For example - אישה (a woman) is pronounced /eesha/ - the Yud/Yod stands for the /ee/.