The artist Nachum Gutman might not be very well known internationally but in Israel he is huge! Not only did he create some amazing pieces of art (he is mainly known for his water colors and sketches but did do some oil paintings and other stuff too), he was also a famous illustrator for newspapers, magazines, ad campaigns, children's books and more. Due to this, most Israelis do know his work from one place or the other, but if you like art, the museum dedicated to him might be of interest even if you don't, as Nachum Gutman's art is pretty universally attractive, even if it did focus heavily on Israel.
The museum tells you a lot about Nachum Gutman and has a lot of different types of works of his on display. The museum is divided between 2 different buildings, which is a bit weird but is excellent for parents and grandparents especially as it is extremely child friendly, something you can't accuse most other art museums in town of being.
The museum also has a pretty nice gift shop, but a lot of the items, although not all, are for Hebrew speakers only. You will find translations into English in the museum itself, however, so you do not need to know Hebrew to enjoy the museum, but if you are looking for something else than art in the gift shop and do not know how to read Hebrew, the selection will not be the best.
The museum is located in the charming neighborhood of Neve Tzedek, on 21 Rokach Street (yes, there seems to be 2 of these in Tel Aviv for some reason!), and you need to pay an entrance fee of 24 NIS to enter if you are an adult, children enter for free and discounts are available for senior citizens, Tel Aviv residents etc.
If you are able to read Hebrew, you can find out a lot more about the museum on their website.