Here are your options with a minimum (6-10 point) hand:
The Single Raise. You may raise your partner's major suit with 3-card support (or preempt with 5-card support):
|1 2: 6-10 points and 3-card heart support.|
Bid a New Suit at the 1-level. You may bid any new 4-card suit at the 1-level, starting with the lowest 4-card suit you have:
|1 2: 6+ points and at least 4 hearts (forcing).|
Partner should raise if he also has 4 hearts (since he knows you have an 8-card heart fit).
NOTE: You may not bid a new suit at the 2-level. Such a bid shows a stronger hand.
Raise Your Partner's Minor. Since a 1 or 1 opening usually shows a 4-card suit, you need 4-card support for a raise:
|1 2: 6-10 points and 4-card club support.|
Also, you should not raise your partner's minor if you have any 4-card majors: bid them first.
Bid 1NT. You may bid 1NT if your hand does not fit into any of the above categories:
|1 1NT: Shows 6-10 HCP.|
This is a catchall bid to show that you have enough strength to respond, but not enough to bid at the 2-level.