Please, help me understand tensor products

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I'm reading Webb's A Course in Finite Group Representation Theory, but I keep getting stuck on tensor products and keep rereading the definition, but I just don't really understand it.

$R$ is ring and $H\leq G$ subgroup and $V$ an $RH$-module.

$$RH\otimes_{RH}V \cong V$$

So I think the first side of the isomorphism should have elements in the form of $r_1h_1(r_2h_2\otimes v)=rh(1\otimes v)$ for some $r\in R, h\in H$ and $V$ has elements in the form of $rhv$.

So the map

$$rh(1\otimes v) \mapsto rhv $$

should be fine, right?

Thanks in advance!

PS.:Recommendations on books about tensor products (that even I would understand) preferably with exercises and solutions would be welcome!